R Leaflet eaxample

places <- data.frame(lat=c(50.501472,50.512253,50.450967,50.459447),
                     lng=c(30.498219,30.498519,30.522637,30.490880)
                     )

places %>% leaflet() %>% addTiles() %>% addCircleMarkers(, popup=c("study here", "live here", "city center", "work here"), clusterOption = markerClusterOptions())