St Martins-in-the-Fields Crypt, Trafalgar Square (0171-930 1862). Providing a haven from the surrounding bustle, the crypt features gravestones set into the floor, stone pillars, and a brick vaulted ceiling. It's graced with the presence of Nell Gwynn and the first Winston Churchill. It encompasses the London Brass Rubbing Centre, a name-search centre (filled with Americans looking up the history of their surnames), a bookshop and restaurant. Have tea after leapfrogging gravestones. Admission free.

Highgate Cemetery, Swain's Lane, N6 (0181-340 1834). Still in service as a burial ground. Among the more famous who reside under the earth are George Eliot and Karl Marx. Bizarre Victorian buildings, the Lebanon Circle, Egyptian Avenue, colonnades, chapels, and catacombs make for a sombre day out, accessible by guided tour on the western side. Visit the eastern side for pounds 1, provided no funerals are taking place. Sunday tours: 11am-4pm on the hour.

Barbican Cinema Barbican Centre, EC2 (0171-638 8891. Cinema hotline 0171-382 7000). Spend the afternoon in the Barbican's cinema, below street level, followed by a bevvy in the bar. From 6-19 October a season of popular African films will be featured as well as ongoing current releases. Performance times vary, tickets pounds 6. Concs available on the day.

Wagamama 4 Streatham St, off Coptic St, WC1 (0171-323 9223). Subterranean Sunday lunch in minimalist surroundings. Still hugely popular for its low prices and huge portions, which include freshly cooked Japanese staples such as noodles, chicken raman and yaki soba. Meals are served from 12.30pm- 10pm.

The London Dungeon 28 Tooley Street, London SE1 (0171-403 7221, info line 0171-403 0606). Not for the fainthearted, this medieval horror museum depicts superstition, torture and death through waxwork displays and other reminders of the gory past. The latest exhibition takes a look at Jack the Ripper. Open 10am, last admission 4.30pm. Tickets pounds 7.50.

The Underground Hospital Dover Castle, Kent (01304 201628). Access to the hospital is through "Hellfire Corner", the Napoleonic and Second World War tunnel system within the cliffs. The hospital was built in 1941 and was used during the war as a casualty dressing-station. Visitors can experience a recreation of the hospital during wartime. Tours start at 10am, last admission 5pm (until 31 October, when last admission is 3pm). Tickets pounds 4-pounds 5.50.

Le Shuttle Turn up at the Eurotunnel UK terminal at Folkestone, stick the car on the shuttle and arrive at Calais 35 minutes later. Special offers before 19 Oct for a day trip from pounds 39 or overnight stay from pounds 49. Book on 0990 353535.

Exeter's Underground Passages (01392 265858). Britain's only ancient city passageway, originally designed to bring water to Exeter at the start of the 13th century. Today's water board has devised a more modern system (but not necessarily as efficient), allowing you to wander through the passages amid tales of ghosts, rats and the financial wheeling and dealing associated with the provision of the city's water.

National Caving Association (01639 849519). This isn't dangerous if you do it with your local club, of which 330 exist in England. Take a caving and potholing course of two to six nights at the Rock Lea Activity Centre exploring Derbyshire's intricate cavern systems, or explore the underground world of the Peak District with the Edale YHA Activity Centre.

Dolaucothi Gold Mine Pumsaint, Llanwrda, Dyfed (01558 650359). Enjoy an underground jaunt to this mine, first exploited by Celts and Romans 2,000 years ago and last worked in 1938. There is an exhibition centre and, if you feel lucky, have a go at gold panning - can't be any more dicey than the National Lottery. Open until 3 Nov, 10am-5pm, admission pounds 1.

Compiled by Roopi Makkar