The Scarlet, Cornwall: Two's company at this hotel

Cornwall's new The Scarlet is design-conscious, eco-friendly – and child-free. "We like children and they would have a ball here," says Rebecca Hughes, one of the three sisters who have just opened this hotel, "but Scarlet is intended for adults only, to help couples reconnect." Reconnection is aided by two-person, wood-heated hot tubs overlooking the beach, and "Scarlet Journeys", a sequence of therapies for couples designed to help adults re-focus on each other.

The sisters already own one of the UK's first family hotels, Cornwall's Bedruthan Steps, which was built in the 1960s. They opened this 21st-century sibling, overlooking Mawgan Porth, on 1 September. It's an angular building designed by Jon Capel, and full of well-framed vistas. From reception, an infinity pool stretches out to a view of the Atlantic. Modern sculptures and paintings line the walls.

Ecology is a passion for the sisters. Solar panels heat both indoor and outdoor pools. The rest of the heating comes from a huge £120,000 bio-mass boiler that burns locally harvested woodchips. Standard heat recovery, grass roofing and grey-water recycling initiatives are complemented by the staff being paid to pick up litter from the beach in company time.

Inevitably, everyone asks "Why Scarlet?" and there's no single answer except that Rebecca and her sisters liked the name. "We say Scarlet is a green hotel looking out on to the blue of the Atlantic."

The rooms

All bedrooms have views of the sea and Atlantic sunsets. The colour scheme and design of each room is different. "Relaxing levels of colour, like you see in plants," is the hotel mantra. Bedding is sourced within the UK, with all towels, sheets and robes made out of organic cotton. Toiletries are from the Cornish Soap Box Company, which provides little canvas bags in which you can take away your half-used soaps. There is no Wi-Fi, no business centre, and no mobile phone reception. However, for those who cannot cope with digital isolation, ethernet cables are available.

The food and drink

Masterchef Ben Tunnicliffe heads the seven-strong kitchen team. Ben recently sold up his own restaurant in Penzance (the Michelin-starred Abbey) and relished being head-hunted by Scarlet. The dining room is decorated in Black Forest gateau colours – dark chocolate, black cherry and cream. Waiting staff are dressed in T-shirts and baggy, sashed trousers based on those worn by Thai fishermen. The fixed menu changes daily and offers four options for each course. Eclectic cuisine makes good use of locally-sourced seafood, vegetables and meat. Guests are encouraged to take wine by the glass with recommendations offered for each course.

The extras

The hotel spa is one of this place's most radical departures, a subterranean level full of winding corridors and hidden rooms. The intention is to distance the design as far possible from the clinical spas of so many modern hotels. Some of the treatment suites for couples even feature double beds and lockable doors. At the centre of this labyrinth lies Deep Relax. This is a dark, curtained room with large, sailcloth pods full of cushions. Guests are supposed to curl up inside and float away their troubles.

The access

No children or pets, although Jasper the hotel dog can be borrowed for walks. Wheelchair access to all levels.

The bill

Rooms cost from £180 per night for B&B and £250 for half-board.

The address

The Scarlet, Tredragon Road, Mawgan Porth, Cornwall TR8 4DQ (01637 861800; scarlethotel.co.uk ).