You can travel

to Mount Isabel del Torres in a taxi, which is always a hair raising experience in the Dominican Republic.  The taxi rates are usually standard but do not pay until you return to your hotel.  The taxi will wait as long as you want usually. 

There are guides waiting to take you up in the cable car - but beware you have to pay for the guide to travel up in the calbe car as well.   The views from the top are fantastic one minute you are in the clouds and the next the views of the bay are breathtaking.   The cable car ride itself is smooth and the ride down is a lot quicker.