London's Roman Amphitheatre

Guildhall Yard, EC2V

Rome gets all the glory when it comes to amphitheatres. With Gladiator II rampaging onto screens on this week, the Italian capital will once again bask in the free PR for its (admittedly impressive) But did you know that we have London's answer to the big ring right here below our feet? Colosseum.

Tucked away in the Guildhall enclave, close to Moorgate Tube station, is the Guildhall Art Gallery. Dodge through the many building sites and you enter a quiet plaza with a ring of dark stone set into the pavement, tracing where London's Roman Amphitheatre once stood.

Bits of it are, amazingly, still standing, but you must descend into the bowels of the gallery to find it.

Put your bags through a little scanner and you're free to wend your way through rooms of art down various staircases. There, in a dimly lit basement, are the stone and timber remnants of an amphitheatre that was first built in 70AD from timber, before being upgraded with stone and tile some time in the second century, as Londinium reached new cosmopolitan heights.

Roughly elliptical in shape and measuring 100 by 85 metres, it would have been able to hold up to 6,000 spectators. Given that here in 21st-century London we can pack 90,000 people into Wembley Stadium, that might seem quite piddling. But in the second century there were about 30,000 people living in the whole of Londinium. Imagine a venue where you could scream and bay for blood with one in five of your fellow Londoners.