The Place of Salah
The Prophet (SAW) said, in a hadeeth collected by Imam Muslim (may Allah have Mercy on him), ‘…unlike any other messenger… the whole earth has been made a place of worship (mosque) and purification for me and my ummah’[Abu-Dawood].
This is explained by the muhadditheen (scholars of hadeeth) that a Muslim can and should pray when it is time for AsSalaah, anywhere he wishes. As long as there is no obvious najasah in it and it is not a place of worship forbidden by the Prophet.
"AsSalaah- A Muslim’s Prayer As commanded by Prophet Muhammad (SAW)" by Abu Mustafa Arshad Khan, October, 2004, UAE. Pg - 38.
‘Beware of those who preceded you and used to take the graves of their prophets and righteous men as places of worship, but you must not take graves as mosques (turn graves into mosques, or have graves in mosques); I forbid you to do that.’ (Muslim)
"AsSalaah- A Muslim’s Prayer As commanded by Prophet Muhammad (SAW)" by Abu Mustafa Arshad Khan, October, 2004, UAE. Pg - 38.