Heritage Open Day: A chance to climb the rare double helix staircase of St Editha's Church. Tamworth. on Saturday, 14th September between 1100 and 1400. The stone staircase of St Editha's Church, Tamworth, built around 1400, is of a rare double helix construction, where two staircases twist around one central post, similar to DNA. This staircase is the only complete example in the UK, in that it ascends from ground level the full height of the church to the battlements. Therefore you can ascend the outer staircase, walk around the battlements, then descend the inner staircase viewing the bells and ringing room.