Complex sentence: Using Roman roads, pilgrims headed to Coimbra and had to reach Porto before night falls, as the gates of the city closed, once in the pilgrims headed to Church of São Martinho de Cedofeita (c.1087).
Split into simpler sentences: Using Roman roads, pilgrims headed to Coimbra and had to reach Porto before night fell, as the gates of the city closed. Once in Porto, pilgrims headed to Church of São Martinho de Cedofeita (c.1087).