Elias and Agistros could be one , however they are two beaches, seperated by a small rocky line in the middle. Both are sandy with shallow and cold waters and their only real difference is their size. Elias is much bigger than Agistros.
Plenty of umbrellas and sun chairs are enough for every guest since the big distance from Skiathos town makes the two beaches be really quite even in the high summer There are no watersport schools or beach bars so most of the times sea waves will monopolise in your ears. In Elias however, there is a small tavern with delicious fresh fish meals and Agistros has a canteen for sandwiches and soft drinks.
The area is accessible by car or motorbike from a dirt road. You can just turn north at bus stops 21 or 23 and follow the road in each case. If you choose to move from bus stop 23, you have to change from asphalt to dirt road. Adventurous hikers must be well equipped since journey can take than 1 hour.