Palm-fringed beaches? Check. Crystal lagoons? Check. Tropical rainforests? Check. The twin-island nation of St Kitts and Nevis embodies everything travellers have come to expect from the Caribbean, except, that is, for the crowds.

Somehow, this vibrant island state has remained under the radar of mass tourism, carving out a niche as an alternative destination for those looking to avoid more mainstream Caribbean islands.

The smallest sovereign state in the Americas, St Kitts and Nevis are compact and easy to navigate, which is just as well because the pace of life here is slow – and proudly so.

St. Kitts is the larger and more developed of the two and is home to the laidback capital, Basseterre, a former colonial outpost renowned for its historical monuments, vibrant markets and lively beach life.

Dominated by Mount Liamuiga, a dormant volcano carpeted with verdant rainforest, Kitts is also home to the defunct British fortress, Brimstone Hill, one of the best-preserved citadels in the Americas and a UNESCO World Heritage Site.

Remnants of the sugar cane industry, once the beating heart of the Kitts economy, remain; old sugar plantations have found new lives as bijou hotels and restaurants, while the island's narrow-gauge railway, once used to transport the cane, has become a popular attraction.

And then there's Nevis. Fanned by trade winds and dominated by an active volcano, this island is the quieter of the two. The scenery remains relatively unchanged by progress; its undulating landscape is punctuated by plantation-style hotels which offer lazy lunches and charming lodgings.

Those looking for something more adventurous can pass the days hiking through forests, pedalling down mountain trails or surveying the island's coral reefs, which are popular with scuba divers and snorkelers.

There is little competition for space on Nevis' powdery beaches, and, for the discerning gastronome, there are plenty of excellent restaurants to choose from.

St Kitts and Nevis will, alas, not stay under the radar forever. The authorities are keen to boost tourism and those familiar with this corner of the Caribbean will be hoping they do it without diluting the islands' many charms.