Saturday, 27 October 2013, with SMA 8 students and PLP team, I have eco-trip to Bantul, Yogyakarta Indonesia. This trip called ?SIMUSA? . What the unique of our trip is we go to Piyungan Bantul by bike. Its distance from Yogyakarta city is about 8 kilometers.

Piyungan is one of districts in Bantul region, Yogyakarta.  It has great natural view. One of places that we?ve visited in Piyungan is Pegunungan Sewu (one of karst areas in Java island).

Pegunungan Sewu  is named for the mountain range that extends lengthwise along the southern coast of Yogyakarta, Wonogiri (Central Java), to Tulungagung (East Java) in Java, Indonesia. it  formed by the removal of the sea floor thousands of years ago. Limestone characterizes these mountains.

This mountain has a very unique karst landscape, it is characterized by the existence of the phenomenon on the surface (eksokarst) and subsurface (endokarst). Surface phenomena include the formation of positive, such as karst hills which amount 40,000 ?conical hill. Notching negative form is karst valleys and karst lake.

Phenomena include subsurface karst caves which amounted about 119 caves have stalactites and stalagmites, and all the underground river. Because of the uniqueness of the ecosystem, then in 1993 the International Union of Speleology proposed for Pegunungan Sewu to be one of the world's natural heritage.

In our trip, we also  found many floras. One of the floras is Pohon Jati (Tectona grandis). Pohon jati is one of indigenous species in Karst  areas in Java. We felt so happy with this activity. Lastly, we hope can raise the awareness to protect our nature through this activity.