Still Existing Polish Medieval Castles Established by Casimir III the Great

King Casimir III the Great (reigned 1333 - 1370 A.D.) is considered the greatest ruler of Poland. One of the main reasons why Polish Kingdom stopped to be a regular battlefield was fortification system and army reformation that he and his court envisioned. He strategically placed or rebuilt 53 castles and surrounded 27 cities with brick walls. Unfortunately, due to turbulent history of Poland, not many of these buildings survived in one piece. The map below present most prominent and still existing pieces of castle architecture that were initially constructed on King Casimir’s orders:

Code used for map:

castles_lat <- c(50.327222, 50.053889, 51.250528, 52.058611, 50.03419,
                 51.37536, 50.244214, 52.541417, 49.780458, 51.40172,
                 50.67608, 49.562306)
castles_lng <- c(19.129167, 19.934722, 22.571733, 19.203611, 20.2174,
                 20.28932, 19.780036, 19.688325, 22.765103, 21.14261,
                 21.74732, 22.209389)
castles_geo <- data.frame(lat = castles_lat, lng = castles_lng)
castles_popup <- c("Castle in Będzin", "Wawel Royal Castle in Cracow", 
                   "Castle in Lublin", "Royal Castle in Łęczyca",
                   "Royal Castle in Niepołomice", "Castle in Opoczno",
                   "Piaskowa Skała Castle", "Mazovian Prince's Castle in Płock", 
                   "Przemyśl Castle", "Radom Royal Castle", 
                   "Castle in Sandomierz", "Royal Castle in Sanok")

require(leaflet, quietly = T)
castles_icon <- makeIcon(iconUrl = 
                         "http://simpleicon.com/wp-content/uploads/castle.png", 
                         iconWidth = 30, iconHeight = 30
)

castles_geo %>%
  leaflet() %>%
  addTiles() %>%
  addMarkers(popup = castles_popup, icon = castles_icon)