This apartment is a 5 minute walk from the cathedral, a 5-10 minute walk from the Alcázar, 10 minutes from all the shops off Plaza Nueva, and close to lots of good restaurants, Tapas bars, and even better Gelato shops (we would recommend Bolas and La Abuela especially).
The hosts are incredibly helpful and will go over local landmarks, shops, and some good Tapas bars and leave you with the map so you can find your way around Sevilla when you first arrive.