Eden Project

The site was an exhausted china clay pit, 60 metres deep and sterile, when work began in 1998; the gardens opened in 2001. The engineering is the first thing you notice - two clusters of geodesic domes clad not in glass but in inflated hexagonal pillows of ETFE, a fluoropolymer film that weighs a fraction of glass and lets the frames span large distances. Inside the Rainforest Biome, the largest indoor rainforest anywhere, paths climb through banana, cocoa, coffee and rubber to a canopy walkway near the roof, where the heat and humidity are held at tropical levels. The Mediterranean Biome is cooler and drier, with olives, citrus and Californian and South African planting. Outside, the pit floor carries terraced crop gardens on soil manufactured on site from clay waste and composted green material.

What you actually see

• The Rainforest Biome - tropical crops and a canopy walkway under ETFE.
• The Mediterranean Biome - olives, citrus and dry-climate planting.
• The outdoor terraces - crop gardens on soil built from clay waste.
• The domes from the rim - the whole pit seen from the entrance path.

When to go

March to October for the outdoor gardens, which are bare in winter. School holidays are very busy; arriving at opening buys a quiet hour in the Rainforest Biome. Winter brings an ice rink and light events, and the biomes work as an all-weather option any time of year.

Honest expectations

Entry is expensive for a family and the food inside matches. The Rainforest Biome is deliberately hot and humid, uncomfortable for many and briefly unbearable near the canopy walkway; there is a cool room to retreat to. The site is a deep pit, so the return walk is uphill unless you take the land train, which queues.

Nearby

The Lost Gardens of Heligan lie south, and the Cornish coast is twenty minutes away.