The legendary object in the 2009 Doctor Who episode “The Pandorica Opens” is the Pandorica.
“The Pandorica Opens” is the first part of the fifth series finale of Doctor Who. It was written by showrunner Steven Moffat and first broadcast on BBC One on 19 June 2010. In the episode, the Doctor and Amy Pond investigate a mysterious prison said to contain the most dangerous being in the universe.
The name deliberately echoes Pandora’s Box, but the Pandorica is a fictional device within Doctor Who’s time-travel mythology. Its mystery draws together clues from earlier episodes and brings numerous alien powers to Stonehenge in the year 102 AD.
The story continues in “The Big Bang,” which was broadcast the following week. Because the two episodes form a single finale, the Pandorica is often discussed alongside the later revelation of what it contains and why it was constructed.