It's sunday and sunday is Rastro and La Latina day. To enjoy the last really good, almost summer weather the perfect plan is La Latina, terrace, friends and "party".
Passing by Plaza Mayor and going down on Calle de Toledo you will find the beginning of La Latina, or going all Calle los Cuchilleros where the famous oldest restaurant Botin is placed you will come to Plaza de Puerta Cerrada.
Going down Segovia you will find La Divina Comedia, a very good and popular bar, very good atmosphere.
But if you want to start with a very excellent (or dinner later) lunch then Cava Baja will offer you very good food at Madrids most famous restaurants, Casa Lucio or Julian de Tolosa for example.
If you continue on Calle del Almendro, one of the streets going out from Cava Baja, then you can go to a little bar called Almendro 13, beers for 1,30-1,50 and very good tapas.
But if you stay at Cava Baja you will find a lot of bars, Lamiak is one of them, a very good one and popular.
On the end of Cava Baja you will come to Plaza de la Cebada on one side and Plaza del Humilladero on the other side. On both "plazas" you will find different terraces. La Potente for example or La Tomasa.
At the end of Cava Alta, almost in Plaza de la Cebada, you have El Viajero, one of the best places in spring/summer, with their roof terrace. Very good, don't miss it.
On Plaza del Humilladero you can go down on Constanilla de San Andres and Plaza de la Paja with the church on one side, there you can find other bars and terraces and lots of people and good atmosphere. Delic Cafe is a popular spot. Or you can go straight to Calle de los Mancebos where there are other options, one of them, Ugly Paddy, an irish pub.
Other streets with a bit of the same, would be Calle del Humilladero and Calle de Toledo also...
La Latina is full of places and surprises, you will absolutly find one/several you like. Enjoy this sunday!