On 25th April which you know is a Public Holiday there are 2 activities taking place at SMdPorto in aid of the Bombeiros.
The first is "IV Passeio De BTT"
At 7.30 the Bike Ride starts on the "Rota da Concha Azul" 2 distances 25 km's or 50 km's - cost 8.00€'s without lunch -13.00€'s with lunch.
The Ramble starts at 9.00 - cost 3.00€'s without lunch -8.00€'s with lunch
You can register @ http://www.bvsmp.com