This is a series of puzzle caches based upon the UCI World Tour. Each puzzle builds on the next and they will get increasingly more challenging as you progress through the series. The puzzles will lead to a trail of caches along official cycle routes and therefore are best done by bike. The caches are small and will not contain swaps but could cope with a small TB or geocoin.
The Volta a Catalunya traditionally finishes with a stage in Barcelona but it's not a sprinters stage as the race often includes the Alto de Montjuic climb. The 2014 and 2015 final stages both involved tackling the climb eight times. It's a 2 kilometre climb at 5.7% with the steepest section at 8% just before cresting. The final ascent is crested with just 3.9 kilometres to the finish line so this stage favours the climbers and puncheurs with Alejandro Valverde winning the stage in 2015 athough overall honours went toTeam Sky's Richie Porte.
Take your virtual bike to the start of the climb at N 41° 22.350 E 002° 09.215. Somewhere on the 2km climb is a bus stop (there's several in fact!) but this one has a line of large stone spheres going up the left hand side of the ride as you ascend. Immediately after the sphere is a small park with benches. There are A stone spheres before the park. In the park are B stone benches, C wooden benches and D decorative eggs like structures (I suspect this isn’t the correct architectural terminology!) at the ends of the stone benches.
Subtract (A-D)(B+C+D) from your Northing for Stage 10.
Subtract (A-B-C-D)D(B+C+D) from your Westing for Stage 10.
You can validate your puzzle solution with certitude.