For prices as low as 138 C$/pp, you can find flights to Baden-Wurttemberg depending on where you are departing from. On average, flights to Baden-Wurttemberg cost 1,075 C$/pp.
The majority of momondo users who fly to Baden-Wurttemberg tend to spend time in Stuttgart, which is visited 275% more often than other cities. When flying to Stuttgart, the most popular airport to fly into is Frankfurt am Main Airport.
The closest airport to Zoo Heidelburg is Frankfurt am Main Airport, and would make for the quickest drive. For those interested in a secondary airport to fly into, consider looking at flights heading to Stuttgart Airport.