built a new, larger pilgrims' chapel and added the sculptured stone frieze which can still be seen today, showing scenes from the life of St Miren. It was originally brightly painted and may have been part of a rear panel of an altar before being put up as a frieze on the wall. A succession of fires and the collapse of the tower in the 15th and 16th centuries left the building in a partially ruined state. Although the western section was still used for worship, the eastern section was widely plundered for its stone. From 1858 to 1928 the north porch and the eastern choir were reconstructed on the remains of the ruined walls by the architect Macgregor Chalmers. After his death, work on the choir was completed by Sir Robert Lorimer. Points of interest Paisley Abbey is the burial place of all six High Stewards of Scotland, Marjorie Bruce who was the mother of Robert II, and the wives of Robert II and King Robert III. The Celtic Barochan Cross, once sited near the village of Houston, Renfrewshire, is now inside the abbey itself. The cross is thought to date from the 10th century. In the abbey's nave, the Wallace Memorial Window, which depicts the image of Samson, was donated in 1873. Paisley Abbey Drain In the early 1990s an ancient vaulted drain of extremely fine construction, probably 13th century in date, was rediscovered running from the abbey to the White Cart. The drain is thought to date from AD 1350-1400 and is at least 90 metres long, up to 2m wide and up to 2.2m high. The drain contains stonemasons marks on the walls, and marks where gates used to be. Before accessing the drain, water has to be pumped out. Paisley Abbey Drain is designated by Historic Environment Scotland as a Scheduled Ancient Monument and has similarities to other monastery drains, such as Fountains Abbey, Dundrennan Abbey and Melrose Abbey. A virtual tour of the drain is available on YouTube. Archaeological investigations and excavations took place in 1996, 3–16 September 2009, 2–12 September 2011 and 4 September 2013 and many items discovered. Some of these are now on display in the abbey. These include: a slate with music marked on it - which is believed to be the oldest example of polyphonic music found in Scotland imported cloth seals chamber pots from c.1500 tweezers carved bone