Well, I hope it stays that way, as it might have become my favourite city in Spain. I've been twice recently. The first visit was in May, and, true to form, we experienced both warm sun and cold, torrential rain during the three day stay. (Tip no. 1: Take clothes for all weathers in Spring.) I returned for 4 days in July 2020 and suffered 35 degrees, and with no air con in the AirBnB room.
Hotel accommodation is quite limited so you should try to book up early. I stayed the same Airbnb twice, as it is in the historic calle Balboraz, cost 20€ a night for a single room with shared bathroom, including breakfast with homemade cake. Free carpark 2 mins walk at the bottom of the street.
For history lovers Zamora is a dream, home to over 20 Romanesque churches, a castle, and the cathedral, which houses the most spectacular medieval tapestries in Spain, is stunning. There are a host of gorgeous 'modernistic' buildings from the early 20th century. Also, the restored 'acenas' (watermills) are very interesting to watch in full swing. Because Zamora is small, it is all walkable.
If you are sporty, the serene River Duero is flanked by paths which are popular for walking, jogging and cycling. There is also a small beach on the south side, opposite the watermills, with a busy restaurant. Canoeing is also popular. In summer, the municipal outdoor pool, next to the river, is amazing value at 1.32€ half day. (It closes for lunch.) I didn't have the obligatory swimming cap, but fortunately they lent me one. East of the pool is a park with a couple of nice cafes.
One of the best aspects of Zamora is the tapas scene. Local wine and cheese are delicious; drinks and quality tapas are cheap, especially in Calle Herreros. Although Zamora is known for its 'embutidos' (cured meats), there are good vegetarian options to be found.
Toro, a 20 minute drive, is a mini Zamora, also full of medieval delights and worth a day trip. Salamanca is an hours' drive, but is one of the most beautiful cities in Spain and deserves a couple of days' visit at least. Bragança, pic below, is an hour's drive west, in Portugal. The castle is striking, but there's not much to do. I stayed a night, but was bored.
All in all, Zamora and its surroundings are perfect for a peaceful break and I can't wait to go back.
