Harold Reid Reserve is a sandstone bushland and foreshore reserve tucked between Middle Cove and Castle Cove on the shores of Middle Harbour, managed by Willoughby City Council. The signature Sugarloaf Crescent loop is a well-groomed four-kilometre circuit that takes roughly one and a half hours at a relaxed dog-walking pace, winding across Hawkesbury Sandstone ridges, down into shaded Camp Creek gully lined with mangroves, and out onto the Fig Tree Cove shoreline with elevated views across the calm water to Garigal National Park on the opposite bank. The track surface is a mix of packed earth, sandstone stepping stones and short raised timber boardwalk sections, with gentle gradients that suit medium-fitness dogs and their humans without being a steep climb.

Halfway around the loop you pass the Sugarloaf Creek rock platforms and a wooden picnic table overlooking the water where you can stop for a mid-walk drink and a treat break while watching kayakers drift past on the incoming tide. Informational signboards at the two main entry points detail the reserve's Aboriginal connection with the Cammeraygal people, native birdlife to look out for (including kookaburras, currawongs, rainbow lorikeets and white-bellied sea eagles soaring above the harbour), and the old logging and sawmill heritage of the Castle Cove valley. Vegetation is classic Sydney sandstone bush: tall angophora and blackbutt gums, banksia and acacia scrub, wildflowers in spring, and bracken fern understory that keeps the shady western side of the loop cool even in January heat.

Dog access at Harold Reid Reserve is on-leash at all times throughout the bush tracks, foreshore platforms and picnic areas, consistent with Willoughby City Council wildlife protection rules to protect bandicoot habitat, lizards and ground-nesting waterbirds in the mangrove edges. If you want to extend the walk further, the Sugarloaf trail connects directly at the southern end to the longer North Arm Track shared path, which adds another two and a half kilometres each way heading down to the corner of North Arm Road and the Castle Cove marina. For post-wind-down there is a shaded BBQ area with picnic shelters and public toilets a short drive up the hill on Rembrandt Drive near the Sugarloaf Lookout car park.