[petuniasevan]

In other words, these craft had to be built like a cross between a refrigerator and a fireproof safe, yet with a window to allow imaging.

Not only are we talking surface temps of around 900 degrees F, and atmospheric pressures of 90 times Earth sea level pressure, but also a strongly acidic environment.

Here's an image from one lander.

Venera 9 Lander image of the surface of Venus at about 32 S, 291 E. The Lander touched down at 5:13 UT with the sun near zenith on 22 October 1975 and operated for 53 minutes, allowing return of this single image. The white object at the bottom of the image is part of the lander. The distortion is caused by the Venera imaging system. Angular and partly weathered rocks, about 30 to 40 cm across, dominate the landscape, many partly buried in soil. The horizon is visible in the upper left and right corners. (Venera 9 Lander, surface image)

[snowfox]

84 Atmospheres of pressure and surrounded by an atmosphere of Hydrochloric acid and Iodine, two of the most corrosive substances that we know of. Truly a hellish place.