The Spanish Steps, or Scalinata della Trinità dei Monti, link Piazza di Spagna (Spanish Square) with the French church Trinità dei Monti. The Spanish connection comes from the presence in the piazza of the Spanish Embassy to the Holy See (Vatican City). Construction of the stairway began in 1723 and took several years to complete. It was designed by an Italian architect, Francesco de Sanctis, and funded by money bequeathed posthumously by a French diplomat, Étienne Gueffier. The pathway formed by the steps between the church above and the square below was a symbol of improved co-operation between France and Spain. They were originally named after Trinità dei Monti but that was later superseded. The Spanish Steps are now one of the most popular – and crowded – tourist destinations in Rome.
Answered by Michael Simpson.