Where to go: Falmouth, Cornwall
Talk about charisma. The basking shark – the second largest fish in the world, after the whale shark – can grow up to 11m long and weigh 4.5 tons. It swims with its enormous mouth agape, filtering 2,000 cubic metres of sea water per hour in order to trap plankton in its gill rakers. This summer, The Wildlife Trusts are offering the opportunity to see basking sharks off Britain's west coast. Colin Speedie, a leading marine conservationist and the skipper of the yacht Forever Changes, will take volunteers out to help collect information on basking sharks, as well as monitoring the effects of climate change on marine species. Speedie has been studying basking sharks since the 1980s. "During 2007 we will be re-surveying known basking shark hotspots and other new areas to establish their distribution and habitat use," he says. As well as the sharks, you might also see whales, dolphins, turtles and a wide variety of seabirds.
Where to go: Moray Firth, Scotland
There's something magical about a wild animal that comes to you voluntarily. Watching dolphins is exhilarating, especially when they leap and dive alongside your boat. The Moray Firth is an excellent spot to see them – around 130 are thought to live in the area. Dolphin-watching boat trips leave from the village of Cromarty. On dry land, the best spot to head for is Chanonry Point on the northern side of the Firth. Twice a day, fish surge through the channel and are ambushed by waiting dolphins.
Where to go: Arnside Knott, Cumbria
Wordsworth called them "earth-born stars". Rather more prosaically, a balmy summer's night lit by glow worms makes you feel as if you could be in the Med. Glow worms are actually beetles and it is the females who do the glowing. The key to their fluorescence is a protein called luciferin. Adding oxygen and water produces a chemical reaction that results in a pale green glow. The female can switch her light on and off by increasing or decreasing air to the luciferin layer. Females glow to attract males, who have larger eyes to help them pick potential mates. The National Trust runs glow worm walks at some of its sites.
Where to go: Blakeney Point, Norfolk
If you're looking for sheer cuteness, you can't go wrong with seals. Both the grey and common species frequent our coastline. From Blakeney you can take a boat three miles out to the tip of Cley Beach. In July, the samphire is as lush as the grass at Lord's and interspersed with the purple, papery flowers of sea lavender. This is one of the most popular spots in the country for common seals to rest after a few days' fishing. Although largely solitary creatures, seals do gather in large numbers at certain sites: at Blakeney there are sometimes as many as 600. Summer is a good time to see them because they've just had pups. Their mothers bring them here after they've been weaned; the youngest are about four weeks old. Intermingled with the common seals are grey ones. The key to telling them apart is that the common seals look rather like Labradors, with their round faces and snub muzzles.
Silver-studded blue butterflies
Where to see them: The Great Orme, Wales
The Great Orme is a limestone peninsula with views of the sea and Snowdonia; the south-facing slope is covered in butterflies. Silver studded blues are tiny – about the size of a thumbnail – but there are half a million in the 60 hectare site. When the sun comes out they open their startling blue wings and flutter in small clouds, the males vying with each other to impress the females. The peak season is late June through July. They have an unusual life cycle: the caterpillars exude a sticky substance that attracts ants, which in turn milk the caterpillars and help protect them from predators.
Where to go: Gigrin farm, Powys, Wales
Red kites are a rusty colour, with a wingspan of almost 2m. This beautiful bird was pursued by game keepers and egg collectors and, by 1903, Britain's kites were down to just five breeding pairs. In 1989, conservationists brought kites here from Spain; there are now 3,000 of them. At Gigrin, meat is put out every day, so you can get within a few metres of the birds – close enough to get a good look at those impressive talons.
Where to go: Park Gate down, Kent
Orchids can be irresistibly fascinating, with a whiff of the illicit about them. We have 56 species of native wild orchid in the UK and the warm chalk downland of Kent is one of the best places to see them. Park Gate Down, a reserve managed by Kent Wildlife Trust, has 10,000 orchids growing in a tiny area. You're likely to see fragrant, greater butterfly, late spider, musk, pyramidal, common spotted, early purple, lady, as well as the very rare monkey orchid. The latter is only found in three sites in the whole of Britain and, when you look closely, the flower really does look like a gangly spider monkey.
Where to go: Ainsdale, Merseyside
This nature experience is not so much a case of seeing, but listening. Ainsdale is one of the best places to hear natterjack toads calling. Although smaller than the common toad, this little beast is the loudest amphibian in Europe. In spring and summer, the males call to attract mates and their chorus of croaks can carry for a mile. Natterjacks are nocturnal, so one of the best ways to hear them is to go out at night. It's a magical experience standing by a pond, the jet-black surface shimmering with the moon's reflection, the sea whispering on one side as all around toads sing their throaty songs. The toads have fairly flat bodies that are warty brown, olive or grey (the males can lighten or darken their skin in order to camouflage themselves better), with a distinctive yellow stripe that runs all the way down the middle. Males have nuptial pads: hard patches on the inside of their forefingers that they use to grip the female during mating, and large vocal sacs. They're not very good at jumping, only doing it if they are alarmed. Surprisingly, they're poor swimmers and can drown in deep water.
Where to see them: the Farne Islands, Northumbria
Who doesn't love puffins? There's something comical about their plump bodies, parrot-like bills and dapper, plumage. Puffins nest in large colonies on cliffs with grassy slopes, where they dig burrows. A puffin normally lays one egg in its burrow at the end of May; the chick hatches 43 days later. At this time of the year chicks will still be reliant on the parents for food. Their main diet is sand eels, the over-fishing of which has led to a decline in puffin numbers. On the Farne Islands, though, they are doing well: there are around 55,000 pairs, and you'll be able to get quite close. The islands are one of Europe's most important seabird sanctuaries, home to more than 20 different species, including eider ducks and four species of tern – some of which will dive-bomb you , so wear a hat.
Where to go: Rutland, Leics
Ospreys feed exclusively on fish. Their underparts are white, with dark brown above, and their legs have thorny hooks to help them hang on to fish. With a wing span of 150cm, they're impressive birds, especially when hunting. At this time of year the adults will be feeding their young. Ospreys are endangered, because they were hunted by fish farmers and have been affected by pesticides. There are now more than 130 pairs in Scotland, and we finally have the first English-born ospreys for more than 150 years.