The observation tower located in the territory of Sirvėta Regional Park is called Arka due to its construction. It is not high (the observation deck is located at a height of 12.5 meters) and stands out from other towers with its unique construction. It was built in 2013. A spiral staircase leads to the top, which leads to 3 observation decks located on different floors. This observation tower can also be visited by those who are afraid of heights. The Sirvėta observation tower is not high, but it is built in an open area and the landscape of Sirvėta Regional Park opens up from the observation deck. The village of Didžiasali, which has been declared an ethnocultural reserve, can be seen a little more than a kilometer away.