The calculated distance (air line) between Buchholz in der Nordheide and Halstenbek is approximately 21 miles respectively 34 kilometers.
By car or train, the actual journey to Halstenbek is certainly longer, as only the direct route (as the crow flies) between Buchholz in der Nordheide and Halstenbek has been calculated here.
Air line (approximately)
34 kilometers
18 nautical miles