Just inside the North Beach car park of the Guana Tolomato Matanzas National Reserve, a statue of a 16th-century Spaniard faces west. Ignoring the shore that lies behind him, his gaze, shielded by a conquistador's helmet, seems to look beyond the immediate. It flickers over the thick vegetation of this lush wetland zone, settling on the bright light of the afternoon sky. And there it lingers, musing on the question posed by the horizon.
A car park – where family vehicles have pulled up for a day on what is an undisturbed section of northern Florida's Atlantic coast – is an odd place for such a monument. But then, this is no ordinary statue – and, if one theory is correct, this is no ordinary location.
Instead, this sculpted figure of Juan Ponce de León is the latest attempt to fix a definitive marker to the precise spot where the USA was conceived. In April 1513, this grizzled Spanish voyager became the first documented European to set foot on what is now the American mainland. He is believed to have landed at a latitude of 30°8'N – co-ordinates that would have had him arriving 16 miles north of what is now the city of St Augustine.
Florida is many things to many people: a giddy enclave of rollercoaster loops, theme-park thrills and excitable children; a tireless party playground where the bars of Miami and Fort Lauderdale scarcely shut; a warm-weather wonderland where a tan is ensured. But it is rarely perceived as a hotbed of history. And as the 500th anniversary year of 1513's major moment has come into play, Florida has developed a taste for its half-ignored past.
The problem is that no one really knows where Ponce de Leon had his planet-changing epiphany. Several facts are uncontested: that he was part of Christopher Columbus's second voyage to the New World in 1493; that he was the first governor of Puerto Rico, but was pushed from power in 1511; that, on being unseated, he decided to look west for "undiscovered" territories; that he and his fleet of three ships departed Puerto Rico on 4 March 1513, sighted the Florida coast on 2 April, and, having waded ashore the next day, probably met native tribesmen as he sailed south trying to map a find which he believed was an island.
But the exact site of the footfall that fomented the first Spanish settlements in continental North America remains shrouded in mystery. That semi-accepted reading of 30°8'N would have been achieved using an astrolabe, a medieval navigational device that consulted the constellations as rudimentary guides, and was not accurate to modern standards. Furthermore, the main source for the crosshairs falling at 30°8'N is Antonio de Herrera y Tordesillas, a Spanish historian who reputedly based his account of the voyage on Ponce de León's own log (since lost) – but was writing nearly a century later in 1601.
The issue has spilled into the courtroom. Four places, strung along 280 miles of Florida's east coast, claim to be the giant X on the chart – St Augustine, the small towns of Ponce Inlet and Jupiter, the sandy strip of Melbourne Beach. In January, the Florida Historical Society staged a mock trial at Palm Beach County Courthouse, where the quartet stated their cases. Costumed actors spoke. "Evidence" was presented. No verdict was returned.
But what is clear to me, as I admire the new statue (it was unveiled on 2 April), is that there is something special about Florida's upper east side. Wandering to the ocean, I realise that this particular beach can be little changed from the day when Ponce de León may have glimpsed it. It has clean, pale sand and a wild verdancy, all wind-battered palm trees and salt-flecked seagrass. Moreover, the stretch of coast that runs from Jacksonville to West Palm Beach is little known to British visitors, despite delineating a state where Orlando and Miami are practically second homes. My plan is to see it all, visiting the four contenders to the title of "America's birthplace" by tracing State Road A1A – which, in cascading 329 miles from the border with Georgia to Key West, barely leaves the shore.
Half an hour south of the statue, St Augustine is alive with history. Whether or not it was the first landing site, it was undoubtedly the first European settlement in the future US, founded in 1565 by another far-foraging Spaniard, Pedro Menéndez de Avilés. Its tight grid of streets clings to this era, most notably in the form of the Castillo de San Marcos. Built between 1672 and 1695 to safeguard Madrid's fledgling possession, this fortress of hard coquina blocks was in military use until 1900, and was never taken during this time.
Within, I find ghosts of colonial Spain – cannons jutting over battlements; a musty chapel where a stone altar waits in silence. This theme is replicated in the Cathedral Basilica, which also dates to 1565 – dark wooden beams; deep red décor; light flooding through stained glass. On the rear wall, a set of murals delivers an optimistic treatise on Spain's ingress into the New World, soldiers, missionaries and indigenous Americans praying in unison – with no room to mention the violence and disease that would so afflict the latter.
On the opposite side of Cathedral Place, Avilés Street is the city's oldest thoroughfare. Certainly, it is old enough that the tiny church it once contained, Nuestra Señora de los Remedios, was built in time for colonial Spain's nemesis, Sir Francis Drake, to burn it down in 1586. The Spanish flag still flies at its entrance, but nowadays this narrow strip hides galleries and antique shops, plus a wholly 21st-century restaurant in Cellar 6, where I pause for pan-seared scallops ($25/£16). Nearby, the central drag of St George's Street is thronged with stores and eateries. As a bar, Sangrias sounds like a refugee from the English 1980s, but its long balcony overlooks a hive of humanity to fine effect, and the Ancient City Classico version of its titular tipple ($8/£5) is rich with orange and cherries.
St Augustine is the heart of Florida's 500th anniversary celebrations. Birthday presents range from Colonial Quarter – a family-friendly recreation of the Spanish city of yore, complete with musket demonstrations, which opened on St George's Street in March – to a Spanish food and wine festival, all gloopy olive oils and rosy riojas, scheduled for October. Then there is the exhibition that is currently dominating the main Visitor Centre. The staging of Picasso: Art & Arena (until 11 August) – a selection of the great man's scratchy depictions of bullfighting, on loan from the Fundación Picasso Museo in Malaga, underlines how seriously St Augustine takes its connection to its first inhabitants' motherland.
Leaving on the A1A, I call at St Augustine Lighthouse. The 165ft and 219 steps to the look-out of this 1871 beacon are demanding in the morning heat – but the view supports Avilés's cleverness in placing his project here. At this height, the city's wise position – set back from the Atlantic on the defensible channel of the Matanzas River – is visible. This is the start of a drive that will bring other revelations – not least the prettiness of the initial 50 miles, where towns with such names as Summer Haven and Hammock remember an innocent epoch of American holidays, and Flagler Beach, where I halt for the night, is happily trapped in the Sixties.
Si Como No Inn is a traditional seafront motel, painted in a merry rainbow of colours. It offers surfboards for rent at $20 (£13) per day – an inviting prospect thanks to the waves that break on its doorstep. And there is something similarly alluring about The Funky Pelican, an eatery injected into the restored planks of the pier, where the Pesto Funk omelette supplies my morning nutrition. Outside, a team of local fishermen have already taken up their posts, probing the Atlantic with rods outstretched.
This is America for American holidaymakers: unfussy, relaxed, amazed when overseas tourists happen upon it (and few do). So too, in a rather different way, is Daytona Beach, 20 miles further south. Here, in this city of motorsports, local law allows you to drive on the beach (for a $5/£3 fee). Curious, I amble down (on foot) for a closer inspection. Sure enough, a truck is parked next to the dunes, there are tyre tracks on the sand, and speed-limit warnings (10mph) shout their message within metres of children playing ball games – one of those strange situations where, for all its familiarity, America can appear utterly foreign. Retreating to my own car, I fail to suppress a laugh on noticing a sign, infused with self-denial, that asks visitors to leave "nothing but footprints on our beautiful beach".
This environmentally unfriendly regulation stays in force almost as far as Ponce Inlet, where the vista changes again. Gone are the high-rise hotels of Daytona Beach, replaced by rows of boats and a marina community. In truth, its name is the prominent basis for the idea of the area as the landing site, and even this is a slice of opportunism, the town having borne the less romantic title of Mosquito Inlet until 1927. But the panorama seen from the lighthouse that rears to 175ft in Maryland brick shows why the inlet – a wide opening in the barrier islands that shape this portion of the coast – might have attracted a curious explorer. On the water, meanwhile, the Down The Hatch seafood eatery caters to today's visitors.
Below Ponce Inlet the shore becomes fragmented, forcing me inland – then through Port Canaveral, where vast cruise liners occupy the docks. I rejoin the A1A for uninspiring progress through Indian Harbour Beach, where condominiums squat in front of the ocean – only for the Atlantic to reassert its authority at Melbourne Beach. And here, suddenly, is Juan Ponce de León Landing Park, where a billboard announces: "This is a historic site."
Perhaps it is. Perhaps it isn't. The claim is built on the research of a single historian, one Douglas Peck, who re-sailed Ponce de León's route in 1992, and found that the currents brought him ashore here, 125 miles south of St Augustine. Alongside the boardwalk, an information panel declares that "contrary to current consensus, [Ponce de León] landed at Melbourne Beach". It is a bold statement, but whatever its veracity, the beach is an untainted wonder. Another sign advertises that, between March and October, sea turtles nest and hatch here. I dig my toes into the sand, and observe a lone surfer as he strides out to greet the rolling surge. There would be worse places to trip over a new continent.
The last leg of my tour is a flurry of contrasts: gilded gated complexes framing the A1A south of Sebastian Inlet; raw leafiness at Fort Pierce Inlet State Park. Then comes Stuart, an idyllic town where cafes are arranged on St Lucia Inlet (part of Florida's Intracoastal Waterway), and the current exhibition at the excellent Elliott Museum – Leonardo Da Vinci: Machines In Motion (until 23 August) – salutes another 16th-century adventurer.
I reach Jupiter at dusk, drift into a waterside hotel, and wake to birdsong. Outside, Jupiter Inlet is the distant long-shot in the race to be 1513's poster boy, able to proffer no more solid a reason for being America's first landing site than its proximity to the transatlantic Gulf Stream (something that would become a factor as the New World grew, but would have been irrelevant 500 years ago). Yet with sunlight dancing on its surface, this hardly matters. As I watch pelicans dive-bombing the shallows in search of breakfast, a thought that occurred 18 hours earlier as I took a diversion into the protected coastal marshlands of Canaveral National Seashore – and saw the lift-off paraphernalia of John F Kennedy Space Center clambering mightily above the treeline – is reinforced: that whether you are a mariner, an astronaut or a tourist, this glorious region of Florida is ripe for discoveries.
The writer flew with Virgin Atlantic (0844 209 7310; virgin-atlantic.com), which serves Orlando from Gatwick, Glasgow and Manchester, and Miami from Heathrow. American Airlines (0844 499 7300; americanairlines.co.uk) and British Airways (0844 493 0787; ba.com) fly Heathrow-Miami; BA also flies Gatwick-Orlando.
A week's fly-drive package, including return flights to Orlando from either Gatwick or Manchester plus car hire, costs from £699pp (based on two sharing) through Virgin Holidays (0844 557 3859; virginholidays.co.uk).
Seven days' car rental with Hertz (0843 309 3099; hertz.com), picking up from Orlando Airport, costs from £186.
Casa de Suenos, St Augustine (001 904 824 0887; casadesuenos.com). Double rooms from $159 (£104), including breakfast.Si Como No Inn, Flagler Beach (001 386 864 1430; sicomonoinn.com). Double rooms from $85 (£56), room only. Jupiter Waterfront Inn, Jupiter (001 561 747 9085; jupiterwaterfrontinn.com). Double rooms from $154 (£101), room only.