The park is a popular destination for both foreign and Costa Rican tourists. Poás allows tourists to see into the crater of an active volcano. You can often smell sulfur from the crater while visiting the peak, and a couple of hiking trails to see Lake Botos, an acid water lake on a dormant crater.There are many guided tours offered to the volcano through private tour companies or you can catch a daily "tourist" bus provided by the TUASA bus company. The 10.0149079-84.21614711 TUASA bus to Poás will take you to the top of the volcano and then return you to Alajuela after several hours—leaves at 9AM, return 12:30PM or 2:30PM (ask!), US$3 return.Make sure the volcano is not closed due to activity. Probably, it is best to buy the ticket during the bus ride to the volcano (if possible) or at most a day before. The bus driver will know whether it is closed or not. Getting a refund, if the volcano is closed, seems not properly working.