Route: Bilboa to Lisbon - not mountainous

pagd

Hi, I am travelling to Bilboa and on to Lisbon over the next few days.  I have mapped the route as follows:

Provisionally we have decided to go as follows but wondered what you thought:

Day 1 (Nov 17). Bilbao to Salamanca

Day 2. (Nov 18) Salamanca to Badajoz

Day 3. (Nov 19) Badajoz to Cascais, Portugal.

 So we would be driving less than 300 miles/ day. We have a satnav.

Would anyone suggest another route please?

I have tried the michelin route finder on CC site but just get ferry information!

Thanks