Creating modern faux-stone geometric backyard obelisks is a simple and affordable way to add a touch of contemporary elegance to your garden. By using everyday plastic bowling pins as a base and submerging them into heavy gray cement, you can transform these inexpensive items into stunning outdoor decor. This DIY project allows homeowners to repurpose ordinary items into a sophisticated piece that enhances the visual appeal of their backyard, all while maintaining a budget-friendly approach.
These obelisks should be strategically placed in a garden bed or along a pathway to create visual interest and draw the eye upwards. Pair them with lush greenery or colorful flowers for a striking contrast. Their neutral gray tone complements various garden styles, from modern minimalism to rustic charm. Arrange them in groups of varying heights to create a dynamic display. Consider adding LED ground lights to highlight their geometric forms during the evening.
Cement-Embedded Plastic Pin Obelisks

Materials
10 cheap plastic bowling pins
Heavy gray cement mix (enough to fill a large bucket or mold)
Large plastic container or mold (big enough to fit the bowling pins)
Mixing tool for cement
Protective gloves
Dust mask
Directions
Prepare your workspace by laying down protective sheets to catch any spills or splashes.
Wear protective gloves and a dust mask to ensure safety while handling cement.
Mix the heavy gray cement according to the instructions on the packaging until you achieve a smooth, consistent texture.
Pour the mixed cement into the large plastic container or mold, filling it to a depth that will allow the bowling pins to stand upright without tipping over.
Submerge each plastic bowling pin into the cement, ensuring they are evenly spaced and stand upright. The thick cement will stabilize the pins in place.
Allow the cement to cure for the recommended time, typically 24 to 48 hours, ensuring the pins are fully stable and the cement is hardened.
Once the cement is completely dry, carefully remove the mold, revealing your new geometric obelisks.
Position the obelisks in your backyard as desired, using them as standalone pieces or in combination with other garden elements.

Variations & Tips
For a playful twist, consider painting the plastic bowling pins in various colors before submerging them in the cement. This will create hidden pops of color visible only at the base or edges, offering a surprise contrast to the gray cement. Alternatively, experiment with different shapes of plastic items, such as small plastic cones or bottles, to create obelisks with unique profiles and textures. Adding decorative stones or glass marbles into the cement mix can also provide a subtle shimmer and texture to the obelisks' surface, enhancing their aesthetic appeal.