Spain orders two-week quarantine for incoming travellers from 15 May

All incoming travellers from overseas will be quarantined for two weeks

Spain

The travel ban to Schengen region will expire on 15 May, but the European Commission has asked countries to extend the restriction until 15 June at the earliest.

But as you can see with the case of Spain, they are not waiting to allow non-essential travel back into the country. And the issue here is going to be if there is no consistency in the approach that European countries will be taking in this regard.
Spanish authorities will at least impose a two-week quarantine period for incoming travellers but this will only apply to those entering the country during the period of 15 May to 24 May – when the state of emergency is due to end.
It’s a delicate situation since this could easily prompt travellers to just wait out the ten-day period and travel on 25 May to avoid any quarantine.

As for the rest of Europe, it makes things rather complicated as you have countries like France who has said that they will keep their borders closed until at least mid-June.