• The locked doors of some of the most famous buildings in London swing open this weekend for public perusal. Explore the Foreign Office, the Hoover Building - even the Bank of England - and all for free (09001 600 061)
• Be bowled over by the haunting sounds of Tibetan singing bowls at the Pavilion Theatre, Brighton. Projected paintings of Himalayan scenes by Russian artist and mystic Nicholas Roerich will complete the meditative experience. Adults £7.50, concs. £5 (01273 709 709).
• Boer War battles are reconstructed at Audley End House near Saffron Walden, Essex. Period artefacts are also on show. Adults £5, children £2.50, children under 5 and English Heritage members go free. (01799 522 399)
• Transport yourself back to the sixteenth century at Lyddington Bede House in Northamptonshire (01793 414910), where period court and country dancers will be performing. Adults £3.50, children £1.80, free for under-fives and English Heritage members.
• It's your last chance to visit Abbotsbury in Dorset and see the world's biggest swan colony before the birds fly off for the winter. Cygnets will provide a great show as they try out their clumsy wings. Adults £5 (01305 871 858)
• Go where no man (or woman) has gone before and take on The Science Museum's new exhibition, 'Star Trek: Federation Science'. Beam yourself to another world and discover the mysteries of 'warp drive'. Exhibition and museum entry: adults £12, children £5.75 (020 7942 4455).
• Calling all mushroom lovers! Get your hands dirty on a two-hour 'Fungus Foray' walk, guided by an expert naturalist. A Ted Hughes walk and an 18-mile hike are also on offer as part of West Yorkshire's Calderdale Walking Festival. Walks are free.
• Don your helmet, pick up your axe and head for Tynemouth Castle in Northumberland (0191 257 1090), which has been invaded by Vikings for the weekend. You can admire their shoe-making and pewter-casting skills while the kids take part in a shield drill display. Adults £3, children £1.50, under-fives and English Heritage members go free (01422 842 830).
• Try out your sea-legs at the last day of the Southampton Boat Show. As a grand finale, 20 Chinese dragon boats will take each other on in a spectacular race, and you can wander round the marina's 800 boats, which include four Second World War warships. Adults £9.50, children £1 (0115 912 9130).
• No top hats will be needed as you experience the thrill of the races at The Ascot Festival. As well as the major Stakes, 'Celebration of the Horse' parades will examine the horse's evolution, and funfairs, jousting and pony-rides will give the kids their own taste of adventure. Tickets cost £6-£16, under-16s go free (01344 622211).
