
Mussenden Temple, Co Derry, Ireland
Rome comes to Ireland ... Mussenden Temple, based on Tivoli's Temple of Vesta, in Co Derry. Photograph: IIC/ Axiom/Getty

Hawkstone Park Follies, Shropshire

A classic example of the 18th-century concept of a "sublime landscape" with cliffs, crags, crevasses and caves. Along a three-hour walking route there is a series of follies, including the Grotto Hill, originally a copper mine, with a labyrinth of chambers and stygian passages to explore, the Swiss Bridge, a rustic wooden bridge over a 30-metre chasm and a 35-metre column: climb it for views of 13 counties.
Hawkstone Park, Weston-under-Redcastle, Shrewsbury; 01939 200611;

Mussenden Temple, Londonderry

Frederick Augustus Hervey's circular library, Mussenden Temple, was modelled on the Temple of Vesta in Tivoli, near Rome (he first tried to buy the original). He dedicated it to his cousin Frideswide Mussenden who died at 22 before it was completed. Their supposedly chaste relationship caused a local scandal as the 52-year-old bishop had separated from his wife and sent her away to Suffolk.
Mussenden Road, Castlerock, Co Londonderry; 028 2073 1582;

Barwick Park Follies, Somerset

To relieve unemployment in Yeovil's glove-making trade in the 1820s, the Messiter family built follies on each of the four compass points of their estate. Jack the Treacle Eater Tower is named after a local runner who took messages to London, fuelled by treacle.
South Somerset district council; 01935 462462;

Stancombe Park, Gloucestershire

The Reverend Edwards married for money, but his true love was his Gypsy lover, for whom he built a doric temple above his lake so they could meet in secret. It's reached via a Chinese-style bridge and a shell-covered tunnel.
Stancombe, Dursley; 01453 542815; by appointment only

Culzean Castle, Ayrshire

In the late 1700s Robert Adam converted Culzean into a sham medieval castle, adding a Romano-gothic viaduct based on one he had seen near Hadrian's Villa at Tivoli, and two "crumbling" towers. There's an octagonal cottage on the island in Swan Pond for nesting birds. There's also a powder house, for the storage of gunpowder, shaped like a chimney in case there was an explosion, and a changing pavilion on the beach with a little splash pool refreshed by the tide.
Maybole; 0844 493 2149;

Westonbury Mill Water Gardens, Herefordshire

This modern folly project was started in the 1990s by Richard Pim at Westonbury Mill in the Welsh Marches, comprising a public garden with cafe. There's a crenellated stone tower, with gargoyles spouting water, and a dome made from sherry bottles.
Pembridge; 01544 388650;

An exhibition, Follies of Europe, runs at the Hove Museum and Art Gallery (01273 290200, until 3 May

Linda Wade packaged Follies of Europe: Architectural Extravaganzas