Poland

Plates long white + blue strip left (EVs = green plates)

Bollards: red strip wrapping all the way around (red reflector front, white back; sometimes numbered; thin curved version exists)

Ukraine: Cyrillic + вул. → Ukraine.

Thin concrete holey poles (holes usually NOT reaching the bottom); doubles, A-frames, round concrete

Hungary: Bulky full-length holes → Hungary.

Romania: Romanian ă î ș ț → Romania.

All-white lines; double middle lines very common - good Poland clue

Denmark: Danish æøå → Denmark.

Greece: Greek alphabet → Greece.

B-type (square) guardrails with circular red reflectors - one of very few European countries

Warning triangles: yellow background + thin red border - unique in Europe; prohibitory = white w/ thick red border

Pedestrian sign with a single horizontal line instead of zebra stripes

Austria and Belgium also use horizontal lines - but TWO of them; a single line = Poland.

Austria: One line → Poland; two lines → Austria.

Belgium: Single plain line → Poland; two lines + figure → Belgium.

Direction signs green w/ distinct Polish font (expressways blue); town entry: green name sign + b&w stylised-town sign; chevrons white w/ red arrows

Polish: Ł (unique), Ą/Ę hooks (also Lithuanian), Ć Ń Ó Ś Ź acutes (Ń unique; Ś/Ź otherwise only Montenegrin), Ż dot (unique); consonant clusters, no V but lots of W (only Slavic language), Z/K/C everywhere

Generally flat & green, agriculture + forests (mountains only near the southern border); many tree-lined roads

Neatly tiled sidewalks (grey/light red, varied patterns) - sometimes even tiled roads

Central-European: light/pastel stucco, orange/red/black/brown roofs w/ 'plastic-tidy' tiles; blocky detached homes; communist-era (often renovated) apartment blocks; dense historic downtowns

Very Catholic: roadside Christian shrines + blue-white/yellow-white Catholic flags

Rare Gen4 black or white car (both also elsewhere in Europe)

3-digit regional road numbers cluster by first digit (yellow boxes on signs; 2-digit roads don't follow this); area codes: first 2 digits regional - even the first digit alone narrows a lot

Suffix meta: -owo = north, -ów = south (think Kraków), -ino/-yno = northwest, -ew = centre

Rare bilingual signs: Kashubian (umlauts+accents) → north; German → Opole; Lithuanian → Puńsk; Belarusian → east border; Lemko (Cyrillic) → southeast

South border = hilly/mountainous (rest mostly flat); traditional wooden houses → east (Podlaskie); orchards → around Grójec & Sandomierz

Pole markings: yellow → west+south; black → southeast (+north pockets); white background → Podlaskie (occasionally Łódź); lamps on top of the pole → northeast (+far-south pockets), side-mounted lamps rare in the NE

Gdańsk: Dutch-Golden-Age downtown (Amsterdam-like); street signs: Białystok = turquoise w/ district; Szczecin = green-blue; Poznań = black w/ blue district section

Tatra Mountains (highest, near Zakopane/Slovak border); Hel peninsula: coastal forest road w/ parallel railway