Random photo: two churches in Maastricht
Dad and I have been to Maastricht, The Netherlands a couple of times. For both of us, it's become a favorite destination. The city is chock full of stuff to see, it's medieval core is largely intact, and there aren't that many tourists around. It's ideal as a vacation spot.
On Vrithof Square in Maastricht, two churches sit only a few feet from each other:

On the right sits the Basilica of St. Servatius (St. Servaas in Dutch). It is built on the site of the tomb of the saint, who died in 384 AD and claimed to be a descendant of John the Baptist. At the time, this town was on the northeastern edge of the Roman Empire, and it formed an important bridge between Roman Gaul and not-very-Roman Germany. The presence of a Christian bishop in this region was considered an important political move by the Empire, since the bishop served as a highly visible outpost of Roman influence at the frontier.
Over the centuries after his death, the basilica remained an important spot for pilgrimage and ecclesiastical authority. By the Middle Ages, it had grown so large and its clerical functions had expanded so much that it became necessary to build a separate parish church to handle services for the locals. Hence, the church on the left was built.
The present St. Servatius was built mostly in the 12th century, and the new St. John's Church (St. Janskerk in Dutch) was built in the 13th century; it was named after St. John the Baptist due to Servaas's claim of relation to him.
After the religious wars during the Reformation, St. John's Church became Protestant; St. Servatius is still Roman Catholic.
As we stood on the square, looking at the Protestant and Catholic churches only a few feet apart, Dad said, "Huh. I wonder if they sit there and throw rocks at each other."
I have tons more photos of these two churches here, including interior shots, photos of the saint's tomb, and photos of items in the Treasury which personally belonged to him.