Yes, you need to take one of the tours which includes the Panama Canal. Costa Rica is pleasant. We toured the pineapple plantation which was interesting. They also do a banana plantation tour. The guides are part of a consortium of certified tour guides and they are very knowledgeable and entertaining. For instance, our guide for the pineapple tour was allergic to pineapple - he said it caused him to go into anaphylaxis - yet he still worked that tour and loved doing it.
Just be careful about the Panama tours. The one we did went to some old Spanish fort and then to the canal. The canal part was the best but only lasted an hour or less. We spent most of the time at the boring ruins of the fort and putting up with an annoying tour guide (American who lived in Panama).