title: Plot shapefile city borders on top of cartopy map
body: <p>I'm trying to plot the outline of Bay Area city/town borders on top of a cartopy terrain map using a shapefile obtained <a href="https://earthworks.stanford.edu/catalog/stanford-vj593xs7263" rel="nofollow noreferrer">here</a> and following <a href="https://gis.stackexchange.com/questions/187867/cartopy-plotting-shapefiles">this example</a>. For some reason, the borders don't show up, even when I specify borders are on top via  <code>zorder</code>. Am I missing something?</p>
  
  <pre><code># import functions
  import matplotlib.pyplot as plt
  import cartopy.io.img_tiles as cimgt
  import cartopy.crs as ccrs
  from cartopy.io.shapereader import Reader
  from cartopy.feature import ShapelyFeature
  
  # Create a Stamen terrain background instance
  stamen_terrain = cimgt.Stamen('terrain-background')
  fig = plt.figure(figsize = (10, 10))
  ax = fig.add_subplot(1, 1, 1, projection=stamen_terrain.crs)
  
  # Set range of map, stipulate zoom level
  ax.set_extent([-122.7, -121.5, 37.15, 38.15], crs=ccrs.Geodetic())
  ax.add_image(stamen_terrain, 12, zorder = 0)
  
  # Add city borders - not working
  filename = r'./shapefile/ba_cities.shp' # from https://earthworks.stanford.edu/catalog/stanford-vj593xs7263
  shape_feature = ShapelyFeature(Reader(filename).geometries(), ccrs.PlateCarree(), edgecolor='black')
  ax.add_feature(shape_feature, zorder = 1)
  plt.show()
  </code></pre>
  
  <p><a href="https://i.stack.imgur.com/ZGehz.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/ZGehz.png" alt="No shapefile borders! Why?"></a></p>