Mystras, the last intellectual site of the Byzantine Empire - Peloponnese Peninsula, Greece

The early-morning view looking over the valley below Mystras. 

Rick Steves says about Mystras (Europe through the Back Door, 2011), “Although it’s famous and on the way, skip Mystras.  Yes, it was once the cultural capital of the Byzantine Empire, but today there’s just not much to see.”   I beg to differ.
The site that Rick favors,  Monemvasia (also on the Peloponnese), he describes as having "ruins all across its Masada-like summit".  I spent hours atop Monemvasia and absolutely loved wandering the paths, but frankly, there are far less ruins there than in Mystras, a World Heritage- listed site.    As Lonely Planet points out, “Monemvasia was the principal commercial centre of Byzantine Morea – complementing Mystras, the spiritual centre.” 
 Do visit Mystras, and wander along the remains of streets, peering into what's left of houses and visiting a palace, a convent (still maintained by nuns and many cats), churches, chapels, libraries, a small museum, and a monastery and discover richly-covered frescoes still intact, and view colorful and intricately decorated manuscripts and books; this is where they wrote and drew them!  If you’re lucky you might be able to glomp onto a small tour group.  Brush-up on German, however, because Mystras seems to be off the path of American tourists.
As for Rick Steves, I like the guy.  I watch his TV programs, buy his books, listen to him on the radio and  have attended his talks in Edmonds, WA, and shop at his store.  I figure he must have had a bad day; too much rain, anxious to get back home at the end of a two month update-the-books trip, or whatever.  Sometimes it happens.  A place you love, someone else just pans or even worse, hates it!  I've been to Mystras twice; in the fall one year, and in the spring another.  We virtually had the place to ourselves!  Go and enjoy.  Imagine what it must have been like 300 or 400 years ago full of 40,000 citizens.  You won't regret stopping.

More buildings in this photo than on the entire top of Monemvasia