Angel Underground Station is one of five stations on the system named after a public house - in this case the Angel Inn, which dates back to at least 1638. It is also the site of the London Undergrounds longest escalator. At 60m in length and with a descent of 27.4m it can also boast to be the longest in the UK.
The station and its escalator gained notoriety when Peter Olenick decided to see if it could be used as a ski run. You can see his video here. Disclaimer: Please do not try this. It's clearly dangerous and is against local by-laws.
Angel Undergound station was originally built in 1901 and its entrance was around the corner from its current location, on the corner of Torrens St. and City Road. It had deep lifts descending to the platforms. As with other stations on the northern line it was originally built with a single central island platform 12ft wide (like at Clapham North and Clapham Common). But due to congestion this became a major safety issue. Consequently the station was rebuilt, re-opening in 1992 on Islington High Street. Because of the distance of the new entrance to the platforms, and their depth, two flights of escalators were required aligned at right angles.
The middle level, at the bottom of the long escalator, is for planned future expansion as a proposed station on the Chelsea-Hackney Line Project (the so called 'Crossrail 2'). But for this, the escalators would have been even longer.
To solve the coordinates of the cache you need to go inside the station entrance to the ticket hall. You do not need to go through the ticket barriers unless you want to ride the escalator. [1] On the north wall is a clock, and to the left hand side of the clock is an electrical box with a number plate below starting ANS nnnnn. The numbers nnnnn are ABCDE.
The final coordinates are given by the following equation.
N 51 32.(A-3)(B)(C+6)
W 00 06.(D+6)(A+E)(Ax2)
For the curious; The longest escalator in the EU is claimed to be in the Namesti Miru station in Prague, Czech Republic (Length 87m, depth 43m), and the longest in the world at the Park Pobedy station in the Moscow Metro (length of 126m, station depth 83m), the deepest in the world.
