I encourage caching by public transport. By now you should know how to get to the Heath - Bus C2 or 214 to Parliament Hill Fields or a bus, train or tube to Hampstead Heath or Hampstead, or also a bicycle will get you close to the caching area.
Hampstead Heath
Hampstead Heath is North London's largest and probably most important green space. The wildest of London's parks has fields to run in, long grass to roll in, woods to hide in and, most famously, ponds to swim in. In north London this is THE place to get back to nature. Strewn with picnickers, cyclists, families and the rest, the heath is large enough and has enough copses, hills and mounds that a quiet spot is never far away.
The Series
You should by now have visited the eleven four caches of the series listed below, and collected the letters (A to L except I) and according numbers.
You can do the caches in any order.
Previously part of the series - now archived:
Parliament Hill, The Pryors, Highgate Pond No.1, Ponds View, The Viaduct, Extension
Cohen's Field
Tumulus
The BONUS / Multi-Cache
It will take you on a short walk across the southern part of the Heath and to a few more interesting locations. The bonus itself shouldn't be too difficult, once you have completed the caches beforehand...
For the Bonus, you will need to visit three more locations as given in the steps below. At each step, you will need to collect some more numbers for the final coordinates.
At the final coords, you're looking for a regular sized, slightly camouflaged plastic box that will hold most swaps and TBs. Parts of the area can be muddy and even though it's a bit off the main paths, you can be seen from several sides (probably more in winter than in summer) - some stealth required! Please take care to replace the cache and the cover so that it can't be seen by muggles!
Original Cache contents include: Logbook, pens, certificates for the first 3 finders, some "Hot Wheels" toy cars, a set of playing cards, a set of colour pencils, a set of colour markers, a small "currency exchange" zip bag containing a couple of coins from Japan and some other countries (feel free to take or leave something), a golf ball, and a number of Geocoins and TB's.
Wheelchair Users
Sorry, this is probably not accessible by wheelchair unless you're able to go offroad - most parts are over grass (which can be very muddy) and uphill/downhill, and the final is in a bumpy patch of forest over a small path.