This is a two stage multi-cache. Stage one will take you to the Pergola. This is a rectangular pergola built by the Waterloo Chapter of the I.O.D.E. in 1907 to salvage and preserve some of the stones from the old St.Andrew's Cemetery (on the site) and from the United Presbyterian Cemetery on High Hill (now Centennial Park). They were being neglected and broken by vandalism. The best of the stones were used to inlay both sides of the walls, inside and out, the pillars and the floor, as well as both sides of the two open ends. The roof is formed of openwork rustic beams. Other stones from these cemeteries were moved to Mountview Cemetery. Some were left buried on High Hill to be uncovered years later and carted off by passers-by to be used as paving stones, garden enhancers or even, in one case, as a soldering table. The original recording was done in 1984 by Janet Eberhardt and Norma Huber. In the fall of 1994, the City of Cambridge had the pergola dismantled and completely rebuilt. The stones were cleaned and replaced in their original postion, except for one from the inner west wall (that of Ronald Wilkinson) which obviously was further broken and ended up in a muddle of pieces on the floor beneath its original position. Most of the stones on the walls look well-preserved and surprisingly legible for their age. The park is situated on the site of the Old St. Andrew's Church on Lansdowne Avenue, near St. Andrew's Street, in the Galt part of Cambridge.
Now, read the plaque at stage one. Find the YEAR construction of the church was completed. Divide this number by 1000 and Add it to 20.140. The result will give you the North coordinates. Now, find the YEAR this church was demolished. Divide this number by 1000 and Subtract from 21.550. This result will give you the West Coordinates. Goodluck.