Buses to the beaches of Poneloya and Las Peñitas leave from Subtiava Market in the western part of the city. Fortunately, I was staying in the vicinity so I could easily walk there. Otherwise, you can take a bus, taxi or walk, it's about 1,5 km from Parque Central. The Poneloya/Las Peñitas buses leave every 45 minutes, from 4:30am to 6pm. You might wait until the bus is full. It will be packed with people even standing in the aisle. There are no fixed stations so it will stop as soon as anyone wants to get on or off the bus. Expect the journey to take at least 40 minutes. The local bus is cheap (10 cordobas in December 2010) and money is collected by the conductor.
The bus heads for Poneloya first and stop for 10 minutes in the bay at the end of the village. Then it turns around and goes back the same way it entered, making a right turn to Las Peñitas where the road ends. Since there are no fixed stops, you need to tell the driver where you want to get off.
We wanted to spend Christmas Day in Las Peñitas. But when we arrived to Subtiava Market there was already an endless queue of people waiting for the bus, and all the buses leaving to Poneloya/Las Peñitas were totally packed. It seemed like everybody wanted to go to the beach that day. So we decided to take a taxi instead. Even that wasn't easy. We have finally found one with three people (a family of locals) already sitting inside. But they said it was ok for them if we wanted to join. The driver charged us 100 cordobas which we found a good price. It only took us about 15 minutes to get to Las Peñitas. A few days later, in a quiet day in the middle of the week, I spent another day in Las Peñitas. This time I went by bus which was just fine, only it took a bit longer.
A taxi within León was 15 cordobas (July 2009) so I took one from the hotel where I was staying to Subtiava Market. Subtiava Market is situated about 1,5 km from Parque Central in León, and it is from there the buses to Poneloya and Las Peñitas are leaving. I took the bus leaving at 9.10. It was 10 cordobas (0.50 cents) and it took about one hour. The buses normally take 40 minutes to reach Las Peñitas, but there was a lot of road construction along the road at the moment.
When the bus arrives to the coast it turns north and goes through Poneloya. At the end of the road it turns and goes back through Poneloya again, then it turns south to Las Peñitas. The road ends in Las Peñitas, just outside Barca de Oro. Some people only visit for the day and then it is good to know that the last bus returns to León at 18.40.