Less than an hour
Although these places are outside of the prefecture of Larissa, I can very safely assume that you will have no problems getting there from downtown Larissa in less than an hour, while travelling at the legal speed limit.
Platamona
Platamona, located just a few minutes past the Tempi Valley, is a great place to visit for two reasons, the beach and the castle. Platamona is home to the famous Platamona Castle. An old fortress that is very much worth your while to see. How can I describe it though? Well, you know those old castles that you may have seen in other parts of Greece? Platamona Castle is exactly like those. OK, I think that I provided a very complete description.
Platamona also has a very beautiful beach.
A huge sandy beach that seems to stretch for ever. The beach is lined with coffee shops and food outlets. This is a great place to spend a hot summer day. However, if you are thinking of travelling from Platamona to Larissa city on a hot summer Sunday evening, Plan on spending 3 hours to make the 25 minute Journey due to traffic.
Plastiras Lake
Lake Plastira is a man-made lake just outside of the Karditsa area. There are beautiful mountains with hiking trails and incredible views. You should also visit the Plastiras dam as well, the sides of the dam are full of people selling home made traditional things like honey, organically grown nuts, home made soaps and works of art.
Meteora
Meteora is not just another place near Larissa for you to visit. It's a legend.
If you can only visit one place near Larissa due to a tight schedule, this is the place to visit. I truly don't need to say too much about Meteora as it's the most famous place in the area. Monasteries on the peaks of thin finger-like mountains that seem to defy gravity. Every time I go there I wonder how did they build these monasteries? Something more amazing than the monasteries are the little caves that the hermits lived in. These people would be raised up there with the assistance of the monks and live in these little caves no bigger than about 3 square meters. they would have food raised up to them every day by the monks and they would never leave. In other words a life sentence of solitary confinement. All in the name of God. At least it kept them off the streets. Luckily, that is no longer done. At least not in Meteora.