Launched in October, the new line has already proved "hugely successful", said head of short-haul product Joanne Lynn.

New tours include trips taking in Somerset and the West Country, the Devonshire coast and Dartmoor, and the Peak District.

Riviera’s new solo tours, meanwhile, focus on outdoor experiences and walking; destinations include Cornwall and the Lake District.

"Our selection of [UK] itineraries became our fastest selling holiday range, with a large number of departures in 2021 already sold out," said Lynn.

"We’ve responded to this demand by adding four exciting new itineraries, showcasing even more of the best culture, history and scenery that Britain has to offer, as well as adding dedicated solo options to four of our original collection."

New tours lead in from £499pp and new solo tours from £649pp. They are capped at 25 guests and will be offered in luxury, full-size coaches to ensure social distancing.

Prices include accommodation, experiences, and the services of a tour manager and various expert local guides.

All trips are covered by Riviera’s Covid guarantee, which promises effective health and safety practices and flexible booking options.

Riviera’s four new UK tours are:

• Oxford, Blenheim and The Cotswolds – five days from £599pp. Bursting with history, character and charm, experience the best of the Cotswolds from our base in iconic Oxford. Travel back in time with expert tours of the "City of spires" on foot and by river boat, explore Unesco-listed Blenheim Palace, the ancestral home of Churchill, and wander the chocolate box villages of the Cotswolds.
• Bath, Somerset and Glastonbury – five days from £499pp. A county steeped in history, there’s much to uncover on this fascinating Somerset tour. From the ancient streets of Bath and Roman settlements to the meticulously preserved prehistoric stones of Avebury in nearby Wiltshire and gothic cathedral of Wells. Not forgetting a boat trip along the river Avon, a trip to the famed musical village of Glastonbury, and Cheddar – the home of Cheddar cheese.
• Devonshire Coast and Dartmoor – five days from £549pp. Discover the best of the Devonshire coast and Dartmoor. Embrace the rich history of the area entwined with its natural beauty on visits to Harland and Buckfast Abbey, the South Devon Steam Railway, the beautiful Gardens at RHS Rosemoor, and the famously steep cobbled street of Clovelly.
• The Peak District: Chatsworth and Buxton – five days from £599pp. Experience the best of the Peak District, embracing the history, heritage and scenery that make up the heart of Derbyshire. From a base of the spa town of Buxton, we visit iconic stately homes, take nostalgic rail journeys and walk with nature, as well as heading to Bakewell, Matlock Bath and Dovedale.

Riviera’s four new solo tours are:

• Norfolk: Royal Sandringham and the Broads – five days from £799pp;
• Cornwall: Falmouth Bay and St Ives – five days from £899pp;
• Walk and Discover: Lake District – five days from £849pp;
• Walk and Discover: North Yorkshire and the Heritage Coast – five days from £649pp.