Walking from one end of the main historic island of Venice to the other—roughly from the Santa Lucia Train Station (Ferrovia) to the tip of Sant'Elena—takes approximately 60 to 90 minutes of continuous walking. The distance is only about 4 kilometers (2.5 miles), but "Venetian time" is rarely linear. Because the city is a labyrinth of over 400 bridges and nearly 3,000 narrow alleys (calli), you are constantly slowing down to navigate stairs or yielding to other pedestrians. If you stick to the main arterial routes marked by yellow signs (pointing toward "Per Rialto" or "San Marco"), you can maintain a brisk pace. However, if you venture into the quieter residential sestieri like Cannaregio or Castello, you will likely encounter dead-end canals or "hidden" squares that add time to your journey. Most travelers find that while the city is physically small, the lack of motorized transport and the sheer density of architectural distractions mean that a cross-city walk usually turns into a half-day affair. It is an incredibly walkable city, but your progress is dictated by the flow of the canals and the height of the bridges rather than the length of the road.