The Great Big Tree Climbing Company, set up by two tree surgeons to show the pleasurable side of their daily routines, arranges events as well as children’s parties at various locations in the UK including London (in Alexandra Park, for example). Open to all ages (‘from three to 100’) and all levels of fitness, participants squirrel their way up to heights of 100 feet kitted out with proper ropes and safety harnesses.
Price: Ticket costs vary, from ££15 per child.
Info: 0800 055 6760; bigtreeclimbing.co.uk
Incongruous as it may seem, 14-year-olds and above can go white water rafting just a few yards beyond the M25. The action takes place at the same Lee Valley venue where Team GB won both gold and silver medals in the canoe slalom in the recent Olympic Games.
Price: The exhilarating, 300m grade 4 white-water course costs from £49.
Info: 0845 677 0600;
Station: Waltham Cross
Originally known as the Millennium Dome, this flying saucer of a structure is best known as a performance venue, hosting everything from championship tennis to rock concerts.
But the newest action takes place on the roof, with an epic 90-minute guided (and fully harnessed) walk with 360-degree views from the summit.
Price: Tickets cost from £26 for adults and children. Children must be at least 10 years old, minimum height 1.2m. One adult must accompany every two under-18s.
Open: From 10am to between 6pm and 10pm, depending on the season.
Info: 020 8463 2000; theo2.co.uk
Tube: North Greenwich
Big Bus Tour: Stop 20 & 21
Accompanied by the theme music from James Bond, you’ll zip along the Thames at gut-busting speeds on a RIB (Rigid Inflatable Boat, ie one with a solid bottom). Guaranteed to blow out the cobwebs, the boats carry 12 passengers who are provided with weather-proof gear. Options range from a 20-minute jaunt to a 75-minute trip travelling from Embankment Pier as far as the Thames Barrier.
Price: Tickets cost from £23 for adults; £20 for children.
Open: Daily from 10am to 7pm.
Info: 020 3245 1177; thamesribexperience.com