Protecting a valuable garden bench in a city garden requires a multi-layered approach. First, make the bench physically difficult to move. The safest method is to permanently anchor it using a concrete foundation. Dig post holes, set the bench's legs in concrete, or use heavy-duty ground anchors and security bolts designed for outdoor furniture. This makes it nearly impossible to lift or carry away.
Next, add a visible deterrent. Use a high-quality, weather-resistant steel cable or chain lock. Thread it through the bench's structure and around a fixed object, like a mature tree or a buried anchor point. Consider using tamper-proof security screws to fasten the bench seat to its frame, thwarting disassembly.
Integrate the bench into your garden's overall security. Ensure the area is well-lit at night. If possible, position it within view of your home or a security camera. You can also discreetly mark the bench with a UV pen or engrave a postcode for identification.
Finally, choose the right bench from the start. Opt for incredibly heavy materials like solid stone, thick cast iron, or dense hardwood. Some modern designs are made from reinforced, vandal-resistant polymers. While not completely theft-proof, these measures dramatically increase the effort and time required for theft, encouraging thieves to seek an easier target. Regular checks and maintaining a presence in your garden are your final, crucial layers of defense.