Eastern Panama includes some of Panama Province and the whole of the largely impenetrable Darien Province plus Kuna Yala.
Darién is the easternmost province of Panama. The area is heavily forested and undeveloped, and it is literally the end of the road for the northern section of the Pan-American Highway, which ends in the village of Yaviza. The wilderness that follows until the road starts again in Colombia is known as the Darién Gap, and is an extremely dangerous area plagued by Colombian narcotraffickers and guerillas.
Kuna Yala is limited in the north by the Caribbean sea, in the south by the province of Panama, in the East by Colombia and in the west by the province of Colon. The area it covers is 3206 km2 and stretches over 373 km. The coast is lined by an archipelago of 365 islands, 49 of them inhabitated. According to the census of 2004, Kuna Yala had 36,487 inhabitants. The region enjoys a certain degree of sovereignty within Panama, as constituted by the 'ley organica 16 de 1953'. The Congreso General Kuna, which meets twice a year, is the highest political authority of Kuna Yala. The economy of Kuna Yala depends mainly on agriculture, fishery and tourism industry. Farming is mostly for subsistence; the traditional crops are guineo, corn (maiz), sugarcane and some coconut.
The Darien Gap is the one break in the Pan-American Highway, meaning that overland travel across Central America is pretty much impossible. This 60 mile gap without roads has been successfully crossed a handful of times - usually by expeditions equipped with off-road vehicles and staffed by special forces types. Attempts to bridge the gap with a road have stalled, partly because of environmental protest and concern that an overland route may expose North America to foot and mouth disease from South American cattle.
Crossing by a combination of foot and boat is not only possible but relatively easy - as long as you stick to the Caribbean side and "hedgehog" from resort to resort, thus avoiding the dangerous inland zone.
Darién is a spectacular destination for anyone interested in pristine rainforest. That said, this is absolutely not a place to go unless you do your homework first. The Darien Gap is a haven for drug cartels and paramilitaries, making it one of the most dangerous places in the world. Attempting to cross the Gap on foot will most likely get you into more trouble than you can handle.
The areas of interest for tourists are not in the Gap zone but be aware that the entire province is a rough place and you should definitely hire a guide if you decide to explore the forests here.