Up at The O2

Up at The O2 is a guided climb over the fabric roof of the O2 arena, the former Millennium Dome on the Greenwich peninsula. Climbers are fitted with a climbing suit and harness, clip onto a safety line and follow a guide up a walkway that rises over the curve of the roof to a viewing platform at the summit, about 52 metres above the ground. From there the panorama takes in Canary Wharf, the river bending around the Isle of Dogs, the Thames Barrier downstream and, on a clear day, the City skyline further west. It is a different view of London from the usual tower-top observation decks: you are outdoors, moving, and part of a small group rather than standing behind glass. The booking page describes a climb of around one hour thirty minutes, and two versions are sold, a Daytime Climb and a Snow Globe Climb Guided Experience, the second limited to groups of twelve. The climb is physically undemanding in the sense that the walkway is a steady incline, but it is outdoors, so weather matters.

Preparation is simple. You arrive at Peninsula Square, check in, are issued kit and given a safety briefing before heading to the roof. The gradient is gentle and the pace is set by the guide, so most reasonably mobile people manage it comfortably. Age, height and fitness limits apply, and the operator lists the exact criteria on its own pages, so check them before you book if you are bringing children or anyone with a health condition.

Wear flat, closed shoes and dress for the weather, since the roof is exposed to wind even in summer.

Choosing between the climb versions comes down to what you want from the view. A daytime slot gives the clearest sightlines and good photographs of Canary Wharf, while the Snow Globe experience is a more playful, group-focused variation. Other time-of-day climbs, such as sunset and twilight, are sold through some channels, and the best advice is to look at the options on the date you want. Clear days are better than grey ones, and a low sun in autumn and winter can be spectacular on the glass towers.

The O2 area is an easy add-on to a Greenwich day. North Greenwich station is on the Jubilee line, and the river services and cable car also serve the area. Combine the climb with the Cutty Sark and the Royal Observatory for a full day downriver, or pair it with a river trip back toward Tower Pier.

The honest caveat is that it is a premium-priced activity for a relatively short experience, and it is weather dependent, so it rewards people who want something active and different rather than the classic sightseeing checklist. For those people, it is one of the better active experiences in the city.