Maps below. Alghero is at the bottom edge in the middle of the map of Europe. Alghero is on the northwest coast of Sardegna.
The two smaller maps show bike rides in green, train in orange and car/bus in black.

Below, an aerial view of Alghero, Sardegna. Mi amore. You can see the long sea wall right to left. That is a medieval wall. The red tile roofs most visible closer is il centro vecchio. The old town. Further above a patch of green, a large park with the modern down town just to the right. There is a lungomare, a sea side promenade, along the shore line from left edge of the foto to off the foto to the right. It is my fav lungomare in Europe. Fotos below will show more. Much of the old town is car free. Much of the lungomare is car free. There is a bike way along the lungo mare except in the old town. Some of the medieval wall still exists away from the sea.
Captions with the fotos below will explain more. The population of Alghero is about 45,000 but there are many more visitors in the summer. Alghero is a very popular seaside destination for Italians. A bit off the beaten track. There is modern airport 5 miles from Alghero. Also a large regional park - Porto Conte. Temperatures rarely fall below freezing. Palm trees and bougainvillea everywhere.  I have been to Alghero both summer and winter. Much quieter in the winter. My 3 months winter stay counted only 6 indoor days because of rain, wind or chill. Winter lowest average temps bottom out at mid 40s to upper 50's. Awesome bike riding.
Summers are warm. Typically low 70's to mid/upper 80's but could be warmer. The beaches are very popular.