Aircraft
What astonished me was the aircraft. The Gotha that attacks the town was an amazing machine. With a wing span of about 77 feet, it could cruise 500 miles, yet only flew at 87 mph. Compare that with what we have today, and it's hard to believe it's been less than 100 years since they we used.
Were the scenes with the dogfights all staged, or was some actual archival footage used? Someone out there must know.