For the fit and adventurous-minded I highly recommend a walk down the full length of Lamu beach. Once you get away from the tourist-haunted strip of sand next to the small town of Shella you will have almost the whole 12km to yourself. You will find peace and seclusion, lost camels and thousands upon thousands of small pink crabs basking on the shore line. Be quick if you want to catch one, and watch your thumb! Make certain that you take enough water with you, however, and a blanket or umbrella might proove useful to ward off the afternoon sun. At the far end of the beach (and island!) you will come to the small village of Kipungani and an up-market holiday resort run by a somewhat less than welcoming White Kenyan. His staff and neighbours make up for it though and can provide you with fresh water from the tap or a well - very safe and very necessary for the long slog back, which ever route you choose to take.
Unfortunately, dense mangrove swamps make it impossible to circle the entire island on foot (and if you did the distance would be too great to cover in a single day). Thus there are two options for the return journey. One is to retrace your steps along the beach. This is the shortest route and the one most employed by locals. The other is to follow an inland rout with will ventually bring you back to Lamu town. The only problem with this is that it is several kilometres longer and with all the paths and side tracks in the interior you run the real risk of getting lost.
Lamu beach, then, is much more than a sunbathers' paradise. It is also a place of trial and adventure that will bring you closer to the 'real' Africa.