Urb.St.Louis.

I think you're spelling it wrong, it should be San Luis.

On the map of Torrevieja it's the last urb on the right on the CV905 Crevillente road.

No Semi, I think you'll find there could be an Urb. St. Louis. I googled to find it & this came up in HERE

COUNTRY AND WESTERN PARTNER CLASS
Leather & Lace Western Dancers are starting a new Partner Class on Tuesday at Casa Ventura, Urb. St. Louis. Torrevieja at 7 - 9 p.m.
Suitable for all levels so come and join us for fun and friendship dancing to pure Country music.
For more details contact Pat and Barry on 669 585 997

You could well be right though Semi as I've just found THIS & it says Casa Ventura, Urb St. Luis. Torrevieja. Casa Ventura is mentioned in both so it could be either. The HELP Association of Vega Baja charity sale, right at the bottom of the page.

EDITED to say to Acapulco That's More

I've just checked my map again and the only urb shown other than La Siesta in the S section is San Luis.

I also went for a fish and chip supper there when I was last over and I think that was at Casa Ventura.  My neighbours took me so have no idea what road it was in.

Where I went was the place that was in the news because a local doctor (I think) wanted it close down.  They have lots of various things going on there and I think he didn't like the amount of cars that were parking nearby.

Have just seen that our posts have crossed, perhaps St is San in Spanish.