South Bank (Big Ben to Tower Bridge), London SE1 (0171-967 8017) tomorrow, 2pm, free
There are perks - free McDonald's grub and the chance to win tickets to the new BFI London Imax and the Aquarium (right) - for kids who don protective clothing and help pick up litter in the first annual Thames river clean-up and wildlife day. Other activities include an archaeology dig at the Founders Arms pub and visits to the newly reconstructed rockpools at Tower Bridge.
Keep London Farming Capel Manor Gardens, Bullsmoor Lane, Enfield, Middlesex (0181-366 4442) tomorrow, 10am-5pm, adults pounds 4, children pounds 2
As well as all creatures great and small from various city and community farms around London, there will be a Farm Animal and Horticultural Show, plus a chance to explore Capel Manor's 30 acres of themed gardens.
Sulgrave Manor, Sulgrave, Nr Banbury, Oxon (01295 760205) today and tomorrow, 10.30am-5pm, adults pounds 4.50, children pounds 2.25
The ancestral home of George Washington is celebrating the harvest as it did hundreds of years ago. The Lord of the Manor and his cook will be telling visitors about the customs and traditions of early rural England, and there'll also be demonstrations of crafts, from corn-dolly making to willow weaving.
Friends of Thomas the Tank Engine Weekend
Kent and East Sussex Railway, Tenterden, Kent (01580 765155) today and tomorrow, 10am-4.20pm, adults pounds 8.50, children pounds 4.25
Booking is advisable here, when Donald and the other engines will be hauling passenger trains to Northiam and back under the watchful eye of the Fat Controller. Other entertainment includes clowns, Punch and Judy, a Thomas model railway and a Thomas video theatre.
Donkey and Pony Show
Wimpole Home Farm, Arrington, Royston (01223 208987) tomorrow, 11am-4pm, adults pounds 4.50, children pounds 2.50, NT members half price
A gymkhana with an obstacle race aimed at finding the most versatile donkey is among the activities planned at this National Trust rare breeds farm tomorrow. The ponies are Shetland ponies, so there should be a big "aaah" factor. NSReuse content