There is a small park, created in 2005, in the grounds of a ruined palacio hidden away in the heart of Realejo.
In a dusty hot city,with few traffic free plazas, this really is an oasis!! There are graffiti tags all over the place and some plants look a little neglected... but there is shade, grass and the soothing sound of the water feature. It is behind the Supersol supermarket and Santo Domingo church.
The park is surrounded by high walls and crazily is often shut during the siesta period of 2 - 5pm. So best to visit in the early evening.
The street name is Paco Seco de Lucena.
I went into this church in the evening of my first day, somewhat befuddled by the journey and a very grey, wet afternoon's wandering. I thought it was the cathedral...but is soon became clear that it wasn't even though it appears to be in the same building (it's not, it's just that you can't really see the join!)
The Iglesia del Sagrario dates from 1704, being built after the cathedral but sharing its site on...inevitably...what was once a mosque. Its floorplan is the shape of a Greek cross, with the main alter being in the centre and towards the north. I was very taken by the intricate stonework of its interior roofing with its many echoes of Moorish geometric patterns.
I've since learned that the church was built as a scale model of St Peter's Basilica in Rome, which is possibly why I found it so attractive.
Definitely worth exploring...don't just focus on visiting the cathedral. You'll find the entrances to both on Plaza de las Pasiegas.