1.1(of a location) having an atmosphere of strangeness or secrecy.
‘a dark, mysterious, windowless building’
‘His destination was the ruins of Quirigua, one of the mysterious ancient sites that had been described by travellers, but about which little was yet known.’
‘She spends the weekend in a mysterious castle.’
1.2(of a person) deliberately enigmatic.
‘she was mysterious about herself but said plenty about her husband’
‘This will all be done from a floating fortress, a mysterious place of unrivaled dark glory.’
‘That mysterious room always locked up half behind the school on the left is still there.’
‘You could simply read all this as a hymn to growing up in a magical, deeply mysterious city.’
‘Nitrus looked down at his charge, following Zinc back out of the mysterious room into the main complex.’
‘The roof has the same sort of mysterious but simple majesty of a big barn with six wooden trusses and exposed rafters.’