The zone is approximately 500m long and 50m wide; it is bounded to the W by London Bridge and to the E by Quay Walk. The access to the site is via stone stairs to the E of Custom House. These are well maintained, with a handrail but can become slippery at times. The ground conditions on the site are generally firm (sands and gravels) however, caution is necessary as mudlarkers are active on the site, and there are dredged areas masked by deep mud.