Coast / Penglai / Fushan Tunnels day trip.
1-day squeeze between Beijing and Hangzhou. At risk if Beijing slides.
Time-honored Lu cuisine seafood house. 13 Dingxi Rd, downtown Yantai. Quanjiafu hotchpotch, soft-fried oyster, scrambled eggs with agarics. Classic Jiaodong (coastal Shandong) cooking, fair prices.
Yantai's seafood/snack strip - Triple-seafood-with-menzi (rice cake stir-fried with prawns, squid, clams in tahini-garlic sauce) is the signature. Where locals eat. Walking distance from the old harbor.
Cold War sub tunnels near Qingdao.
Coastal wetland in Dawa District, Panjin (Liaoning) whose tidal flats turn vivid red each autumn from Suaeda salsa, an alkaline-tolerant plant. Within Asia's largest reed marsh; state-level nature reserve. Best mid-September to late October.
Panjin, Liaoning. Best in Sept-Oct - your dates work - but ~7h from Beijing.
Former secret Japanese biological/chemical-warfare facility in Harbin operating 1933-45 that conducted lethal human experimentation. Part of the site is preserved as a public museum memorializing the victims.
Harbin. Heavy historical weight, far north.
Annual winter festival in Harbin, Heilongjiang, billed as the largest ice and snow festival in the world. Massive illuminated ice sculptures carved from Songhua River blocks. Late December to late February.
Harbin in JANUARY. Wrong season.