This apartment is in the heart of beautiful Tuscany (have been back to Tuscany 6 times), next door to Volterra and San Gimignano and 45 minutes from Pisa and Florence. We (2 x adults and 3 x children) stayed here in July 2016. The apartment was perfect for us, large double bedroom and smaller bedroom with a bunk bed in it. Spotlessly clean with everything in the apt. that we needed for our stay. The large apartment terrace overlooks beautiful countryside to the west (i.e. gorgeous sunsets) taking in vineyards and olive groves. My children were rarely out of the pool. The tennis court is also a great addition to this place, especially with the invention of 'slow' tennis balls :). Castellare di Tonda complex is nearby where we enjoyed their spa (more than once :)), they also have excellent buffet dining, important for us with smallish children. Other superb restaurants are also nearby (try the authentic pizzeria in Alberi - although they seem to open when they feel like it). The apartment itself has everything you would need including Sky TV and wifi (must-haves for modern young teenagers).
Travel advice - if going to Florence, park at the shopping centre which is the last stop on the tramway and get the tram in. Free parking and tram to centre.
We've already booked again for July 2017 (rare for us to go back to the same place), no better recommendation from me. Enjoy.