Biak-na-Bato National Park is home to several rivers and waterfalls, offering opportunities for swimming and relaxation. The Madlum River, with its crystal-clear waters, is a popular spot for swimming. You can take a refreshing dip in the river and enjoy the coolness of the water. For a more adventurous experience, you can also try canyoneering in the Madlum River. This activity involves navigating through the river's rapids and jumping off cliffs into deep pools. The park is also known for its beautiful waterfalls, such as the Bayukbok Caves and Bahay Paniki Falls. These waterfalls provide a picturesque backdrop for swimming and photography. Just make sure to follow safety guidelines and be cautious when swimming in natural bodies of water. Swimming and visiting the waterfalls in Biak-na-Bato National Park will surely add excitement and fun to your friends trip.