From Plaça del Rei it's worth a detour to see the two best surviving stretches of Barcelona's Roman walls, which once boasted 78 towers (as much a matter of prestige as of defence). One section is on the southeast side of Plaça de Ramon Berenguer el Gran, with the Capella Reial de Santa Àgata atop. The other is a little further south, by the northern end of Carrer del Sots-tinent Navarro. They date from the 3rd and 4th centuries, when the Romans rebuilt their walls after the first attacks by Germanic tribes from the north.
