 The station is in two parts : sub @-@ surface platforms opened in 1868 by the District Railway ( DR ) as part of the company 's first section of the Inner Circle route and deep level platforms opened in 1999 as part of the Jubilee line extension from Green Park to Stratford . A variety of underground and main line services have operated over the sub @-@ surface tracks , but the original station was completely rebuilt in conjunction with the construction of the deep level platforms and Portcullis House which sits above the station . 
