Hertfordshire districts: 1. Three Rivers
Hertfordshire, Bucks Hill
Hertfordshire districts: 2. Watford
Hertfordshire districts: 3. Hertsmere
Hertfordshire districts: 4. Welwyn Hatfield
Ayot st Peter, St Peter's Church
Hatfield, Church Street, Hatfield House (Old Palace/Royal Palace): Historic England, TL2308, wikipedia (1611) (Chess Board / Jeu d' échecs / Schaakbord)
Hatfield, Fore street, Hatfield House Hospitality (Gateway), Historic England
Hertfordshire districts: 5. Broxbourne
Hoddesdon (Broxbourne), St Margarets, Rye Road, Rye House Gatehouse, 1443, Historic England, TL3809, Wikipedia
Hertfordshire districts: 6. East Hertfordshire
Albury, Upwick, north of Upwick Hall, Cart Shed and Granary, Historic England (no picture available) (C19)
Anstey, small farmhouses (C16-17)
Anstey Bury, Pelham Road, House, Historic England (no picture available) (Circa 1600, late C18, mid C19)
Braughing, Church End, house, Images of England (1574 / 1860)
Goldings, Goldens Way, Old Barnados' school, TL3014, Historic England (C19) House and Heritage
Hertford, Castle Street, Hertford Castle (gatehouse), Historic England, TL3212, Wikipedia (ca. 1540)
Little Hadham, Gatehouse at Hadham Hall, Stortford Road, C15-C16, HE
Sawbridgeworth, Sheering Mill Lane-Churchyard,The Old Vicarage, Historic England (no picture available) (1857)
Stapleford, Goldings Lane, Waterford Lodge, Historic England (1871-1877)
Walkern, High Street, Dovecote Manor Farm, TL2826, British Listed Buildings
Hertfordshire districts: 7. Stevenage
Hertfordshire districts: 8. North Hertfordshire
Letchworth Garden City, Letchwordt Lane, Letchworth Hall Hotel, Historic England
Hitchin, Holy Saviour church, Historic England
Kimpton, High Street, Parish Church of St-Peter and St-Paul
Hertfordshire districts: 9. St Albans
Saint Albans, Spicer Street, Ramshaws Almshouses, TL1407 (1846), Historic England
Shenleybury, St Botolph church, Historic England
Flaunden, Flaunden Hill, Sharlowes Farm House, Historic England, TL0100 (no detailed picture available) (rebuilt later C16, mid C17)
Flaunden, Flaunden hill, St Mary Magdalene church, Historic England
Flaunden, Flaunden hill, house
EXTRA:
Aldbury, STOCKS DOVECOT, STOCKS ROAD, 1753, HE (+date)
Berkhamstead, 76-78, HIGH STREET, 1863, HE
Bishop's Stortford, HOCKERILL RESIDENTIAL SCHOOL, DUNMOW ROAD, 1852, HE
Braughing, NUMBER 6 AND FORECOURT WALL, CHURCH END, 1860, HE (chimney-single)
Braughing, BARN AT UPP HALL (N-W OF MANSION), THE WARREN, late C16, early C17, HE
Coleshill, HERTFORDSHIRE LODGE, HERTFORDSHIRE LANE, 1845, HE (bottle-ends)
Essendon, LONDON LODGE AT BEDWELL PARK (PL LONDON GOLF CLUB), 1860, HE
Essendon, PL LONDON GOLF CLUB, 1860, HE
Gilston, HIGH GILSTON, GILSTON LANE, 1856, HE
Great Munden, EAST BARN AT LEVENS GREEN FARM EAST OF HOUSE, LEVENS GREEN, early C19, HE
Harpenden Rural, GATE POSTS AND GARDEN WALL AT TURNERS HALL FARM, mid-late C17, HE
Hatfield, RIDING SCHOOL AT WARREN WOOD, KENTISH LANE, 1860, HE
Hertford, CHAPEL 3O METRES SOUTH WEST OF GOLDINGS, NORTH ROAD, 1923, HE
Hertford, THE SEED WAREHOUSE, MAIDENHEAD YARD, Mid C19, HE
Hertford, GOLDINGS LODGE, NORTH ROAD, 1870, HE
Hertfordshire, BUTTERFIELD HOUSE, 4, HITCHIN STREET, 1870-1873, HE
Hunsdon, WALLS, GATES AND PIERS OF AN ENCLOSURE AT ORCHARD HOUSE, ACORN STREET, Late C16, HE
Little Hadham, CLINTONS, C16-C17, HE
North Mymms, THE STABLE BLOCK AT NORTH MYMMS PARK, TOLLGATE ROAD, 1893-1894, HE
North Mymms, NORTH MYMMS PARK WITH ADJOINING GARDEN WALLS AND HA HA, TOLLGATE ROAD, Countryhouse, 1596-1600, HE
Standon, BARN AT BROKEN GREEN (N / N-E OF FARMHOUSE), STORTFORD ROAD, late C17, HE
Standon, BARN AND FARMBUILDINGS ADJACENT, PAPER MILL LANE, C19, HE
Standon, CHURCH END COTTAGES (almshouses), 1 AND 2, PAPER MILL LANE, C17, HE
Standon, 24, HIGH STREET, Mid C19, HE
Standon, STANDON LORDSHIP W, AND STANDON LORDSHIP E (1 Km SOUTH OF STANDON VILLAGE), BARWICK ROAD, 1540-1546, HE
Stanstead Abbots, FARM BUILDINGS AT EASNEYE DAIRY FARM N OF FARMHOUSE, HOLLYCROSS ROAD, 1868, HE
Stanstead Abbots, THE CLOCK HOUSE, 9, CAPPELL LANE, latest half C17, HE
Stanstead Abbots, ALL NATIONS CHRISTIAN COLLEGE, HOLLYCROSS ROAD, 1867-1868, HE
St. Albans, DARROWFIELD HOUSE, ST MICHAEL'S STREET, 1700, HE
St. Albans, 1-7, WELCLOSE STREET, row of cottages, early C19, HE
St. Albans, 36, SOPWELL LANE, early C19, HE
St. Albans, 30, SPENCER STREET, early C19, HE
St. Albans, 9-17, WELCLOSE STREET, early C19, HE
St. Albans, 2 and 4, FISHPOOL STREET, early C19, HE
St. Albans, 54, FISHPOOL STREET, late C18, HE
St. Albans, 78 AND 80, FISHPOOL STREET, later C18, HE
St. Albans, PHOENIX COTTAGE, 72, HOLYWELL HILL, early C19, HE
St. Albans, 58 AND 60 - 62-70, ST PETER'S STREET, C18, HE
St. Albans, KINGSBURY MILL, ST MICHAEL'S STREET, C18, HE (+single)
St. Albans, 40, VERULAM ROAD, early C19, HE
St. Paul's Walden, The Bury, St Paul's Walden Bury, 1887, HE
St. Stephen, CHURCH OF THE HOLY TRINITY, 1841-1842, HE
Thundridge, WYNCHLOWS, 40/41, HIGH ROAD, C17, HE
Thundridge, THE RECTORY (W OF CHURCH), NORTH DRIVE, 1846, HE
Thundridge, THUNDRIDGE HOUSE AND LINKED STABLE BLOCK, POLES LANE, 1855, HE
Thundridge, POLES CONVENT (FCJ), CAMBRIDGE ROAD, 1890-1891, HE
Walkern, FORECOURT WALLS, FRONTAGE WALL, AND N. WALLED GARDEN AT MANOR FARM, HIGH STREET, 1700, HE
Walkern, FARMHOUSE AT MANOR FARM, HIGH STREET, 1700, HE
Wareside, BLAKESWARE MANOR, 1876-1879, HE
Watford, THE SALTERS' COMPANY, ALMSHOUSES, CHURCH ROAD, 1863, HE
Westmill, BARN RANGE AT WESTMILL BURY FARM (N OF THE BURY), HIGH STREET , C16 or early C17, HE