We will be spending 4 nights in Athens in the spring. I would like to do a day tour or two from Athens. Just wondering if you can recommend places that are worthwhile to visit for the day. We want to stay in Athens as a home base. Thanks.
You can visit the town of Naplio or take a short river cruise to the islands of Hydra or Andros for a day trip
The nearby island of Aegina is wonderful for a day trip. It has most everything one goes to a Greek Island for, especially Spring, off season so less tourists. You can take a ferry in the morning, spend several hours on the island, get a late afternoon ferry back to Piraeus and still have time for a night out in Athens. It's very inexpensive to take the ferry rather than spending a lot of money for a tour.
Bear in mind Athens deserves a minimum of 2 days with 3 even better to fully experience the city. Don't sell Athens short, there's more to it than the usual tourist sites.