Our nice airbnb (East end of Eixample) hosts allowed us to check in very early – we had almost all day to walk around.  We tried seafood at la Boqueria  and liked it, many tourists but still interesting, and then visited the Cathedral. Our itinerary is nowhere near of the actual route, as we were circling around a lot.
Two days in Kraków
My return visit to Kraków old town, 40 years later everything looks the same, exept when I focus on the details and then everything is quite different.  Old recording of  ☞ Hejnal Mariacki (Trumpet Call)  played from the tower of St Mary’s Basilica in the Main Market Square of the Krakow Old Town.
On the way to Europe
Just arrived in Frankfurt from Chicago, staring at ceiling art while waiting for connecting flight to Kraków.

Effigy mounds on Mississippi River
Effigy mounds are ceremonial mounds in shapes of animals, built by American Indians who lived in this area. There are thousands of mounds near upper Mississipi river. ☞ Effigy Mounds National Monument Iowa is a very interesting historical site with good easy hiking trails and great views of the Mississippi. ☞ Wyalusing State Park is just across the river. Good camp site, more hiking trails and half a day canoe trail through the wetland in the triangle between the Mississippi and Wisconsin River. Good weekend spot for Chicagoans.
Lidar of Marching Bears Mound Group

Effigy Mounds National Monument and Wyalusing State Park trail maps