The decision to build the staircase of the Trinità dei Monti was made in 1660, but the work only began sixty years later following the pope's explicit order. They proposed a competition for the design of the staircase, and you are looking at the winning selection: a large staircase with twelve travertine ramps decorated with garden terraces, with a total of 135 steps. Note the alternation of ramps and balconies that snake up the hill separating and rejoining: it creates scenic and extremely varied movement, where straight, curved, and polygonal paths follow one another. In this way, the stairway frees itself from the requirements of overly regular structures and harmoniously integrates with the urban space. Thus any observer coming from a distance can appreciate it first in its entirety, and then admire the richness and variety of its scenic effects as they approach the stairway and then climb up it. Try to do so yourself, and you'll see that it will be the same for you as well.
FUN FACT: even though the square is called "di Spagna", or "of Spain", the Spanish Steps are mostly tied to France. They were in fact requested and financed by a French cardinal and diplomat, which is why the Church of the Trinity of the Mountains also celebrates mass in French, Villa Medici is home to the Academy of France, and the stones at the base of the staircase have fleur-de-lis carved into them!